With any other man, Peggy would be alarmed by that click of the door's lock. She'd worry about how much bigger he was than her- all the better to overpower, to take, and it wasn't as if she'd never been put in that position before. Some men (not just men, people in general were very capable of despicable things, of taking liberties with things that didn't belong to them) got ideas in their heads and let impulse guide them rather than a moral compass.
But this was Steve. Never in her life had she seen Steve willingly hurt a fly, and that went for occasions that were literally life or death, in which he would've been justified in taking harsh action against others. He wasn't going to hurt her now, and that was the only reason she hadn't jerked away entirely.
That, and she was trying not to hurt him, either. Nothing was quite so difficult to face as the big, wounded blue eyes Steve could affect without even realizing it. She suspected the expression would be even more devastating on him now, when he was clearly unguarded in a way that went beyond his usual lack of artifice.
"Steve," she warned again, a little firmer this time. It took effort to keep a wobble out of her voice, especially when his lips brushed her skin, warmer than they had any right to be when she was trying to put a stop to this. Swallowing, Peggy lifted her hand and pressed fingertips very deliberately against his lips, redirecting that kiss before it had a hope of landing. "I think it very likely that either your drinks were incredibly strong, or there was something in one of them." Perhaps both of his drinks, now that she was considering it. Thinking to Tony and his wariness with passing trays, to the way she'd seen others rushing off to be sick, it seemed obvious now. This wasn't an effect she'd seen, but that didn't mean Steve wasn't suffering all the same.