"I was hoping you wouldn't mind," Steve murmured, letting Sam pull them closer and putting his own hands on Sam's hips. "I mean... I know I'm kind of difficult to put up with. You deserve a reward." And he wanted to show Sam that he appreciated - loved - everything he'd done for Steve, especially when Steve had been so preoccupied in what was going on downstairs with his best fried-turned-weapon. So when Sam deepened the kiss, Steve let him have control of it, though he wasn't a pushover when it came to kissing, either. He liked kissing, actually, and he liked letting it lead to more. Especially when they had the time and the privacy for that to happen, because it wasn't always the case.