A/N: Characters aren't mine. Writing is.

This was beta'ed by my boyfriend, so it's probably not as objective as it could be. Oh well...

Reviews make me happy. :)

Also, this is getting an edit as of 8/13/12. I spelled Kathy's name wrong, so I'm correcting it. Thanks for telling me, ToriRenee161. :)

It took him five years of working with her to realize that he loved her, but once he did, slipping into a quiet obsession with her became as easy as slipping on an old coat.

All of a sudden, he started to notice everything about her. The way she smelled on late-night steak outs (vanilla and jasmine, with sweat and gunpowder), her self-deprecating chuckle, even the furrow in her brow when she concentrated on paperwork. When he discovered she liked the musical Rent, he almost bought her tickets for the Broadway show.

The image of her, nude and sprawled, often climbed uninvited into his mind at night. He would stiffen, trying his best to banish her, trying to imagine Kathy in her place. Sometimes, he won, and sometimes these nightly battles ended in shameful self-indulgence.

He passed the point of no return that day in the interrogation room, suddenly imagining her moaning his name as he fucked her. He didn't even realize he'd left the room until he was knocking at Cragen's door, telling him to send someone else in, because he needed to go home. Now.

He knew she'd be pissed, and expected a call (that he wouldn't answer), but all he got was a three word text message: "The fuck, El?".

He lied to Kathy again, and rang his partner's doorbell with good old Catholic guilt throbbing in his chest and a bag of Chinese takeout from the place they both liked.

"It's open."

She was sitting at her kitchen table in a tank top and a pair of pants with a hole in one knee, a glass of what smelled like vodka in front of her. She had been worrying at the threads of the frayed denim when he came in, and she looked up at him. She didn't make a sound as he set the food down and poured himself a glass of burning, low-shelf vodka.

They had too much to drink, yet said too little, but it hardly excused him when he pushed her against the wall in a way that, somewhere deep in the alcohol-muted recesses of his mind, reminded him of his father. She curled her fingers in his hair when he found her nipple through her tank top, and gasped raggedly when he dragged his tongue over it.

In retrospect, he probably should have gone home after his first glass of vodka, or gone to sleep it off in the cribs, or done anything but have another glass and watch her as she silently pulled threads from her jeans. He knew that she was angry that he had walked out of the interview room, angry that he wasn't telling her what was wrong, and drunk enough to think that sulking was a good idea. He should have left when she stood up and poured him another glass, glanced over her shoulder at him, then sprawled beautifully on the couch behind him. He especially should have left when he heard his own voice growl "Stand up, Liv."; should have pulled away when he felt the damp skin on her collarbone twitch under his hand. But now it was too late, and she was curled against his chest, asleep and naked. Her breathing was so shallow it reminded him of Lizzie, and he suddenly realized that this is the woman he should have married. This was the woman whose pregnant stomach he should have kissed, and with whom he should have mooned over their first child.

That was also when he came to his senses. I have to leave.

She rolled over and looked at him blearily as he pulled on his pants and shirt "El…"

He smiled bitterly "What, Olivia? Are you gonna ask me to stay for fuckin' breakfast?"

"You just destroyed us, Elliot."

Standing outside her apartment, he cried for the first time since he found out Kathy was pregnant.

He showered in the gym that morning, and changed into fresh clothes that he kept in his locker. He spent the day doing paperwork, tossing cases to Munch and Fin, despite the fact that he and Olivia were supposed to be catching. Every time he moved, he felt like she had gotten caught under his skin. He wondered if her nails had left scratches on his back, but he was too proud to go to the bathroom and check.

He came home that afternoon to jubilant children and an irate wife.

"Where were you?"

"I slept in the cribs, Kat. I'm sorry I never called you.."

"Olivia called."

His throat caught. "What did she say?"

"That she needed to talk about your latest case. She thinks she figured it out."