He keeps his hands behind his head, fingers laced together, willing himself not to reach for her just yet. She has the right to change her mind, and even if she hasn't she has the right to want to do other things with this day, and he refuses to do anything to overwhelm her or drown her in sensation until he's certain of her choices.

Bucky leans up into the kiss, returning it with warmth and affection and longing of his own.