He got that. Tony at least somewhat understood what it was that was making Steve sad, because if it was just a matter of his future family, he would have said that Steve ought to go for it if someday he wound up going back home. Because there'd have been space for him. Pepper would understand, like she always did. They could probably make it work.
But what was the point? Further heartbreak? Tony wasn't going to make it. That was a fixed event, one he wouldn't change for anything because it had to happen. It was inevitable. Steve didn't deserve that, and Tony was sorry, sure. For Steve and for himself and what wouldn't be, what he would never get to have or see or do. But he wasn't sorry that it was going to happen. Not if it meant Steve, Pepper, Morgan, all the rest got to live.
"You do. Right here and now. I love you. What's better than the present?" He leaned over just enough to press a kiss to Steve's forehead.
And then -- "What?" Whiplash, really. Tony twisted to look at the hammer in the cupboard. "Is that Thor's?"