Twenty minutes later, the alcohol had had the desired effect. Sheldon was feeling pleasantly drunk and had found some music they could tango to. Penny had consumed approximately twice the amount of rum he had, and was sat on the sofa giggling over something unknown.

She got up, wobbling slightly in her heels and feeling her fancy dress swish around her legs (thinking why did I suddenly decided to wear this tonight?) and stood in front of him again. At some point it had gotten dark, and the room was lit by the soft glow from the laptop. Sheldon looked down at her and for once his mind went blank; she wasn't just 'attractive', she was beautiful. This time, there was no hesitation on Sheldon's part. He put one long arm around her back and pulled her close to him, pressing her against his torso. She wrapped her free arm around him and he felt her briefly stroke his back. He could smell her hair and it was as intoxicating as the rum. The sober part of his mind was wondering what the hell he was doing and where it was going to lead. The drunk part apparently had the casting vote and didn't care. He felt Penny sigh and lean into him. Something stirred inside him, and then they were dancing.

Penny was a natural. She kept herself held against him as he led her deftly across the room. He moved quickly and lightly, spinning her and taking delight in her gasps. He felt her hand grab his t-shirt, then slide down his back until she could slip underneath it and feel his skin. He looked down to find her staring up at him, her pupils wide in the dim light, gently biting her lip as she concentrated on the movement. He met her stare and they continued dancing. Then the music was coming to an end and in a moment of what he later thought of as complete drunken madness, Sheldon took her completely in his arms and dipped her backwards.

Before she knew what was happening, Penny was suspended horizontally above the floor. She felt the muscles in Sheldon's arms flex as he held her there steadily. A thrill shot through her as she felt his strength, and without even thinking about it she lifted her head. Her lips found his, and she felt him tense in shock before relaxing and giving in to the sensation.

Sheldon had never been kissed before, and was completely unprepared for the feelings that shot through him. His stomach churned and his head felt light, and a heat ran through his body. Penny's mouth was soft but she kissed him with a passion and intensity that left him breathless. Then his instincts kicked in and he was kissing her back hungrily as he pulled her upright, burying his hands in her hair and cupping the side of her face. She pulled him close and ground her hips against him, feeling him stir against her.

A million miles away she heard her phone start to ring. She ignored it and continued her exploration of Sheldon's mouth, but something tugged at her memory. That ring tone. Jake. The person she was doing all this for in the first place.

"Shit." Penny pulled away suddenly, feelings of guilt overwhelming her. She and Jake had been together a month now; hardly a lifetime but her longest relationship for a few years now, and she cared for him a lot. She knew she had a bit of a reputation, but whatever else she was, she wasn't a cheat. Until now.

"I'm…I'm sorry Sheldon…" she babbled, backing away. "I can't do this….I'm sorry." Grabbing her phone, she dashed out of the apartment.

Whilst Raj and Howard had called it a night after seeing the new Star Trek film for the fourth time, Leonard had stayed on for the late feature. He wanted to be sure that Penny and Sheldon were finished whatever the hell they were doing before he went home. So he crept in after midnight, expecting to find the apartment immaculate and Sheldon in bed. Instead, Sheldon was sprawled unconscious on the sofa, his long fingers curled around an empty bottle of rum.

This probably wasn't a good sign, but Leonard wasn't stupid enough to wake a sleeping and likely still drunk Sheldon. So he threw a blanket over him and went to bed.