His eyes close, leaning contentedly into Bucky's touch, but they snap back open at that question.

He should say that he needs time to think about it. That he can't make a decision like that right now, when part of him wants to promise Bucky anything just so they can stay together, when he isn't sure if he'd just be agreeing because right now, he doesn't know if he believes they'll find a way back. That he has to think about his family, his team, his partner.

At the most he should say that he wants to spend the rest of his life with Bucky, he just can't make any promises where that'll be. He can't promise not to ask Bucky to come back with him instead.

What comes out of his mouth isn't any of that.

"I will if you marry me."