BW told him to go for it at the very beginning of the movie actually. That's what they tied into the commercial trailer before he sky dives out the plane into the ocean on their first mission.
And yep at the bold. Plus, him and Peggy never even really hooked up anyway. Didn't even kiss 1nce. THey were the ones that got away essentially. Considering their circumstances of him returning 70 years later, but unaged, it's rather poetic that he got with her niece anyway. Plus, shyt was in the comics. And lastly, as much as muhfukkas on this site talk about all the dirty shyt they done did or would do too hook up with such and such females, friend, fam or foe, wtf is this even really brought up, considering what I just mentioned in the opening of this paragraph?