Steve & Mary
That was a very common misconception about Steve and Bucky, and for good reason. A lot of the things they did were very much things couples did. It was never like that, they never thought of each other like that, but it was the way they were.
"Now if I can just get her to stop trying to grow up, we'll be just fine." He wasn't ready for his kid to stop being a kid, even if she was.