My opinion on the whole Doctor/River marriage is that he knew that there was no other way to change the timeline, and because she refused to touch him otherwise, he married her in order to save the universe. The whole kissing scene was just so awkward, as well; they just don't have that type of chemistry, and it paralleled too much with PotW with all the gold flashy lights and close ups. PotW was huge and emotional and all about sacrificing one's self for the woman you love, not about a quick impromptu marriage to shut the girl up so he could restore the universe already. Sometimes I feel like she forced him into it, dropping hints that made him feel obligated to marry her, not because he wanted to out of love and devotion. Yes, he cares for River, but I think that is more out of guilt because he failed her and her parents when she was a baby rather than out of love.
What I don't get is that their timelines are supposed to be reversed; her past is his future and vice versa. Isn't she supposed to be Mels at this point? River had just regenerated in LKH, so if their timelines are supposed to be so, she would be Mels, not River. I understand wanting to have a character that is recognizable, but this just puzzles me.