Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/ works/1103058. Rating: Explicit Archive Warning: Underage Category: F/F Fandom: Modern_Family_(TV) Relationship: Alex_Dunphy/Haley_Dunphy Character: Alex_Dunphy, Haley_Dunphy Additional Tags: Sibling_Incest, Masturbation Stats: Published: 2013-12-26 Words: 760 ****** Science Experiment ****** by tornyourdress Summary Haley actually has a few things to teach Alex. It’s like being kicked out of college actually made Haley smarter, which is not how it’s supposed to work. And nicer, too, which means Alex doesn’t actually want to strangle her every time they’re in the same room together. She’s suddenly helpful, telling her about ways to behave around boys, what to do with her hair, and how to – Alex can’t even think the words without her face heating up. When Haley moved out, she finally had privacy for once, which meant trying out her – Science experiment. That’s a good word. Yeah. So she’d wait until everyone had gone to sleep, then stuck a chair under the doorknob just in case (because with her mother, you just never know), and then – holding her breath a little, weirdly nervous and jittery – she’d start. Touching herself through her panties first of all, lightly, and then she’d feel the wetness, know that it was okay if she just pushed them aside a little bit and slipped a finger inside herself – and god, just that was like something new and astonishing and she couldn’t believe this feeling was something she could have all on her own, and did everyone do this, did everyone know about this – She was just starting to figure out what to do next when Haley moved back in, and that meant an end to it all, because she couldn’t if Haley was there, three feet away. It was unthinkable. And Haley would never let her hear the end of it if she knew, like how pathetic it was that Alex needed to do this for herself, that she didn’t have a boy to do it for her. Except then there was that time last week, and ever since then Alex’s been jittery and nervous all the time but in the best possible way. She was almost asleep, and trying not to think about it, and then from across the room there was a little breathy gasp. “Haley?” she whispered. “I’m asleep,” Haley hissed. Except she so obviously wasn’t, and it was like all Alex’s senses were heightened. It was dark but she knew, she knew that Haley’s hands were moving under the covers and oh god it probably wasn’t the sort of thing that was supposed to instantly make her twitchy and desperate to touch herself but – And then another gasp, a sort of satisfied one. She knew even though she’d never quite managed it herself, and it sounded good, it sounded like what she’d been working towards all this time, where she’d still be trying to go if it weren’t for her newly-returned roommate. Only if Haley didn’t care about that stuff then – “Fine,” Alex said to the other bed. “Fine.” And she slipped her right hand between her legs and started, already wet, her clit slippery and sensitive when her fingers moved over it and it was already too much and oh god oh god oh god. The noise that came out of her mouth sounded like someone else, and her legs were shaky and already the high was fading because had she really just done that with Haley so close? “Alex?” Haley’s voice sounded uncertain now. “Did you just, um – ” “You started it,” Alex hissed. The next night Haley pushed the covers off and Alex watched what she did. The night after that, Alex tried it herself, the combination of fingers on her clit and inside her, but it was like trying to be coordinated at sports; her brain just couldn’t work that way. “Let me do it,” Haley said, and Alex thought she meant to show her, but then her own fingers were pressing down hard on her clit and two of Haley’s fingers were inside her and she could hardly breathe because it was just too much – “Oh fuck,” she gasped, and then she sank back into the bed. “I can’t believe you said that,” Haley said, looking at her like she hardly knew her. “It was called for,” Alex said weakly. Ever since then they’ve slept in the same bed, the way they haven’t since they were really little. Curled around each other. Their mom would think it’s sweet, but she can’t ever know about this. Haley says it’s okay, it’s just making sure Alex knows what she likes, what she wants, so she can tell boys – or girls, Haley says, fairly – when the time comes. Alex figures the experiment has to end sometime. But Haley’s got a lot to teach her. And learning is pretty much Alex’s favourite thing in the whole world. Please drop_by_the_archive_and_comment to let the author know if you enjoyed their work!