The jiggling akita pup's mass wobbled as he came down repeatedly. Each descent sloshed the waterbed and sent large waves rolling across its surface. The pup panted heavily.

"J... Jake...."

As he breathed heavily, his tongue stuck out from between his glubular cheeks and lapped at his many chins. 

"I'm... ge... getting... tired...."

His massive body shined in the lamplight; his fur was slick with sweat.  

"I know, Rye, I know, but you remember what your mother said...."

Jake nearly cried out as the akita came down just right, his member tightly enveloped by the pup's thick buttocks. 

"A... at least an hour a day, remember?"

He actually did cry out this time.

"She wants you... to exercise every day...."

Jake gripped Ryan's heavy love handles tightly. The akita wore nothing but a 'Big Dog' t-shirt that Jake had bought him nearly a year ago; it was far too small for him now. It stretched halfway down his belly, but failed to cover his deep navel, his rolling love handles, or his massive lower back. As far as Jake was concerned, these were all fair play, and he groped them constantly as they 'exercised.' As Ryan bounced in Jake's lap, his stomach wiggled atop Jake's, and reached as far forward as the older one's chest. He sat on his knees with his thick legs splayed behind him; they rested alongisde Jake's own. 

Whenever the pup ascended, Jake caught glimpses of the massive pouch of flab that hid away the pup's naughty bits. His eyes wandered higher, to the akita's jiggling chest. He was certain that his wife envied those breasts. 

He was close. He shifted his hands behind the pup, then down along his backside; he took two handfulls of the akita's lardaceous, quivering ass and held on tight. They had done this hundreds of times, and Ryan knew what to do at this point. He stopped bouncing, and shifted all of his weight onto his rump. He gently rolled forward into Jake's stomach, then pressed back again, firmly, into the other's lap. 

Jake grunted as Ryan's heavy frame pressed down on him. His member slid deep into the pup's soft, slick crevice, its head pressed firmly against the base of Ryan's tail. He climaxed for the second time that day, depositing another copious amount of seed between Ryan's massive cheeks.