Steve and Natasha end up in the Zola data bunker, where the Winter Soldier is waiting for them. He incapacitates Natasha, and Zola being the gloater he is, gives step-by-step instructions and play-by-play commentary as the Winter Soldier violently rapes Steve right there on the dusty floor of the data station.

If and how much this changes the events of Cap 2 is up to the author!