Disclaimer: This is an adult story and should not be viewed by those under 18 or those restricted by laws in their own country. This story entirely fictional, all names have been created by the author and have no relationship to people living or dead.

Jennie's Birthday Present

It was Jennie's 21st birthday and I wanted to get her something really special to mark the occasion. She'd always been self-concious of how she looked and liked to dress up when we went out. This wasn't a bad thing since I thought her one of the most beautiful people I'd ever met, and to be going out with her was a dream come true. She's about 5'6" with long straight dark hair, which trails down the waist of her stunning hour-glass figure. Despite her beauty she always felt mediocre compared to women with a larger bust. It's not that she was particularly small, her 30-B bosom looked great, but it still dismayed her whenever she saw a larger lady in the street. It was this unhappiness I would hope to end for her birthday...

On the morning of her birthday we visted her parents where we stayed for lunch and she opened the rest of her presents from friends & family. In the afternoon we headed back to my place where I'd got her present wrapped and hidden. I'd bought it over the internet, and although expensive I thought it worth it. I took Jennie into my bedroom and led her to the wrapped box I'd left on my bed. "Blimey" she said, "that's one big gift!" referring to the 1/2 metre square parcel. She ripped the wrapping paper off my present to reveal the box, reading 'Medium Pressure Bust Inflator'.
"What's this!?" she exclamed, obviously a bit bemused by what I'd bought her.
"Well" I said sheepishly, "I know you're a bit sensitive about the size of your breasts and thought this would end your unhappiness", not quite knowing how she'd react next.
"How's it supposed to work?" she asked "Women pay thousands for surgery, and you think this will work?".
"It wasn't that cheap y'know Jen, and it does look pretty genuine." I replied, "Do you fancy trying it?".
"But will it actually work?" she said quizzically.
"What's the worst that can happen? If it doesn't work, what have you lost?" I replied.
"I suppose I can give it a try." she said, unbuttonning her blouse.

I opened the box, removed it's contents and opened the instruction manual. "Medium Pressure Bust Inflator" I read aloud, "Gives a noticeable increase in bust size without the pain of lengthy surgery". I assembled the components as described in the instructions. The first thing was to connect a pressure-regulator valve to an air-cylinder, which took up most of the space in the box. This was then connected to a length of braided rubber hose, which split into two hoses further along its length. At the split I had to attach a pressure indicator dial, which according to the instructions indicates the pressure in the breasts and also ensures that equal pressure is sent down the two tubes. Onto the end of these tubes I attached the final components: 2 one-way, nipple-clamp valves. To work the nipple-clamp valves are attached to each nipple, the system then carefully increases the pressure supplied to the breasts, which should inflate until the pressure-regulator valve is shut by the user.

"You ready then Jen?" I asked.
"I Guess so..." she replied tentatively.
"You'll have to take that off then." I said, jesturing to her lilac lace bra.
She undid the straps and tossed the bra onto the bed. "There you go", she said smiling. Her perfectly shaped, firm B-cups drawing my attention as the cool air caused he nipples to stand to attention.
I brought one of the nipple-clamp valves up to her right nipple and clipped it on.
"Ow" she exclamed, "That's a bit tight!".
"Sorry! I guess it needs to create a good pressure seal. I haven't hurt you have you?" I asked.
"No, it's just a bit of a snug fit, that's all."
I then clipped the second nipple-clamp valve onto her left nipple and suggested she take a seat on the bed.
"Ready?" I asked.
"As ready as I'll ever be to be inflated like a couple of baloons!" she joked.

As the instructions described, I carefully turned the pressure-regulator valve 1/4 of a turn. "Phuuuft" went the valves and the pressure indicator dial jumped slightly to register that the air-flow had started.
"Oooh!" Jennie said, with a start.
"Are you ok?"
"Err.. I think so, it feels.... strange"
"Strange?" I asked
"Yeah, it's a bit cold. It feels like my boobs are being massaged from the inside!"
The instructions then said to turn the pressure regulator to 3/4 once the air-flow had been established. I did this as Jennie gasped slightly and cupped the underside of her bust.
"Is it working?" I asked.
"I can feel them growing!" she said with a big smile, "They look like they're getting bigger too!"
"May I?" I said, pointing to her breasts
"Go ahead." she replied, taking my hands and placing one on each breast. She pulled my head into her chest and I could hear the faint, distant 'shushing' of the air into her bosom.
"I can feel it too, and you're right they do look a bit bigger as well" I said, as we both grinned at each other.

We both sat on my bed as Jennie's breasts continued to slowly inflate. Every so often I'd look at the indicator dial, each time it would have risen slightly as the pressure in Jennie's breasts had increased. After 10 minutes she had grown a cup size and was now a comfortable C-cup. I could see her breasts were now rounder and seemed to stand further away from her chest, they definately looked...
"Wow, don't they look perky!" she said, pre-empting my thoughts.
"How do you... I mean they, feel?" I asked.
"Ermm, they still feel like they're being massaged, but kind of... tighter I guess." she said.
"Well the pressure dial shows a bit more more pressure inside them, so that sounds reasonable. How big would you like to be?"
"I don't know. I always wanted to be bigger, but never really thought how much bigger." She thought for a moment and said "I think another cup size would be good, yes, a D-cup would be great.. not too big."
"Well, the pressure dial shows you're still well within in the green section, so that should be easily possible." I said. The manual has instructions for how large the breasts should be made, the maximum size apparently varying from person to person. Once the pressure dial reaches the red section the maximum size has been reached. Any further inflation of the bust could have considerable repercussions, or so it said.

We sat there for about another 10 minutes as Jennie marvelled at her new bust line, I'd never seen her so happy before. They were only growing slowly, but I could definately see them expanding. It was like watching a pair of small baloons inflate, with every minute they'd be just that bit bigger and would be reaching that bit further to the sky. "I think that's about the right size" she said, "Also, they're feelling kinda firm" she jestured. I felt her bosom, it was slightly firmer than before, but nothing unnatural. The pressure dial showed about half-way into the green, so I supposed they weren't anywhere near their inflation limit. They certainly looked great though, two round mounds sitting pertly on her chest. To stop the process all I'd have to do was close the pressure-regulator valve on the air-cylinder. I gripped the handle and went to turn it.
"It's stuck open" I said.
"Oh yes, very funny" she cooed, "C'mon, these are big enough, stop playing around".
"I'm not playing" I replied.
"Yeah, yeah... now stop joking, these aren't getting any smaller y'know!" she said sternly, pointing towards her bust.
"I'm not joking! It really is stuck!". I said uneasily
"Well you'd better unstick it!" she said woriedly "I'm plenty large enough".

I grasped the handle again and tried to turn it, but it was still stuck fast.
"It's no good" I said, "It's stuck tight."
"Well I'd better get these things off" she said and grasped the right-hand nipple-clamp valve, "They're getting too big now".
"NO!" I shouted, "The instructions say you can't remove the valves with the air-supply on, it will injure your nipples!"
"Well you'd better do something quickly, they're getting huge!" she said shakily "They're feeling even tighter too!"
Jennie's bust was now nearly an E-cup and the pressure dial showed it had risen three-quarters into the green section. Her breasts were begining to look improbable, they were rounding out even more and beginning to jut from her chest rather than sit on it. I clasped her breasts, they were definately firmer.
"Hold on, I get my tools from the garage" I said
"Hurry" she called as I left the room

Once I'd found my keys, retreived my tool box and brought it up to my room another 5 minutes had passed. I returned to find Jennie sitting on my bed clutching her bosom. Her breasts were noticeably bigger, about an E-cup I surmised.
"Hurry up" she called, "They're far too big and feel tight, and they're still growing!"
"OK, hold on, I've got an idea" I said reassuringly
I found the correct spanner to fit the pressure-regulator valve and got ready to try and turn it with the extra leverage it would give me.

"1, 2, .... 3...." I counted under my breath and then tugged on the spanner to try and close the valve. "Woooshtt!" went the valve as a gush of air shot down the tubes.
"Aarrhh" gasped Jennie as the air flooded into her breasts. "Make it stop, make it stop!!" she called.
I yanked the valve back to its 3/4 postion and the air-flow went back to normal.
"Sorry, are you OK?! Did I hurt you?" I asked
"It didn't hurt, but look at them!" she exclaimed "I'm huge!!!", the rush of air had inflated her bosom almost instantly to an F-cup. "They feel so tight" she said, holding her breasts. I could clearly see that her fingers were making very little indentation into her flesh due to the pressure. The pressure dial was at the top of the green section and I am sure I could see her areolas starting to swell with the pressure.

"Do something!" she cried.
"OK, I'm thinking, I'm thinking", the only option I could think of was if closing the valve increased the pressure, maybe turning it the otherway would stop it. "I have an idea" I said.
"Get on with it,... please!"
I took the spanner again and thrust it in the other direction. "phfffftttt......sshhh", the air surged down the pipes again.
"Aaarrrrhhhhh" Jennie gasped for a second time, her breasts expanding faster.
I pulled the valve back again and the air-flow went back to normal, I couldn't understand how to stop it.
"They feel really tight now" Jennie puffed, "They just feel so tight, and they're huge, I feel like they're about to burst". I grasped her two breasts, they were indeed firm, like well filled baloons. The pressure dial was now well into the red section and I could see her areolas really bulging out from the rest of her breasts under the pressure. And yet the air-flow continued and they carried on growing to where I can only believe would be called a G or an H-cup. Her breasts were now pushing against each other for room such that they could easily have been seen even if she'd had her back towards me.

We both sat there, Jennie looking increasingly concerned as the air continued to flow and the discomfort of her inflated bust increased with their growing pressure. "Any further inflation of the bust could have considerable repercussions" said the manual, and we were well past this point. I had to stop the inflation, there was no knowing how much more Jennie could take. A couple of minutes of thinking later she said tentatively "I think it's stopped".
"How do you know?"
"It's not getting any worse" she replied, "They're still really tight, but it doesn't feel like it's getting worse any more."
I put my ear to her left breast, but couldn't hear the 'shushing' like before, "Perhaps the air-cylinder's empty" I said.
"Well how to we find out? There's no level indicator."
"I could always try turning the valve, if it's empty nothing will happen?" I suggested.
"And if it's not!" Jennie scolded
"Well, we need to find out. If it is empty we can get this thing off of you."
"Are you really sure about doing that?" she asked "My boobs are huge already and I feel full to bursting."
"I'm sure it'll be fine." I assured her "I couldn't hear anything, so I'm sure it's stopped."
"OK, but do it carefully" she said slowly.

I took the spanner again and carefully tried to turn it, after a bit of jiggling the valve shifted and the cylinder let out its final deluge of air.
"Oooooohhhhhh...." Jennie cried as the last of the air streamed down the tubes. Her bust trembled with the final flow, the sides of her breasts bulging as far as they would go.
"It's over." I said looking into her eyes
"I don't think I could have taken any more." she sobbed, "Get this thing off me!"
I carfully unclipped the nipple-clamp valve on the right-hand side, her areola protuding well above her breast's surface with the pressure underneath. As I removed the clamp the pressure forced out her nipple with a 'POP!' and it expanded to twice its normal size. Simultaneously I saw look of sheer satisfaction on Jennie's face, "Are you OK?" I asked.
"Oh... my... god...!" she stammered
"What!? Is everything OK?"
"I,... I've never felt anything like that." she eventually answered. "It was like an electric shock. Like an amazing feeling of relief of having that clamp removed, only 100 times more sensitive".
"There's still the other one to remove. Are you ready?"
"YES!"
I unclipped the left-hand side and her second nipple 'POPPED!' out. This time she looked like she'd almost passed out with the sensation.

After she'd recovered from the extreme sense of pleasure I asked how she felt.
"I feel fine, but my boobs still feel really full. They feel tight, better without those clamp things on, but still really tight. And look at the size of them, they're massive! I only wanted to be a D-cup or something and look at me, they're like an H or a J, if such a thing even exists!"
"I'm really sorry" I said, "I can't find anything in the instructions about how to reverse the effects. All I wanted was for you to be happy" I ran my hand down the side of her cheek, over her shoulder and onto the top of her enormous left breast. It felt firm, like an over-inflated beach ball. "Y'know, I actually kinda like the way you look with those..." I said.
"But they look ridiculous,... I look ridiculous!" she exclaimed.
"No,.. I think you look great" I said, my hand still resting on her left bosom.
"They're not real though and it's not right to have boobs this big, or this firm." she said anxiously.
"Ok, they're different, but in a good way." I reassured her. "I'm sure you can get used to them,... I could" I said cheekily, giving each breast a playful squeeze and making each of her nipples bulge slightly.
"Don't do that!" she gasped
"Sorry, did it hurt?"
"Err... well,... not really, I suppose... It kind of took my breath away, like when you removed the clamps."
"Like this?" I said, pushing her two firm mounds together a little harder this time.
"phoooaaa...." she breathed, "Actually, that's rather pleasant...."

... and so the day went on. We spent the evening 'playing' with Jennie's two new presents, finding out how squeezing her air-filled breasts could arouse different sensations. We were thinking of sending the Bust Inflator back, but a faulty regulator valve may have been the best present I could have bought.....

Jennie after her present

The End...

                                       Chalice

Picture morphed by someone else (I am sorry I do not remember by who) and further editied by me.