I don't have a problem with Diana kissing someone, or having a proper relationship with a guy. I think Gail Simone said in one interview that the idea that Wonder Woman was celibate or whatever was pretty ridiculous, or something along those lines, at least.
What I do have an issue with is the fact it's Superman. Unless it's some kind of flashback, completely out of continuity, or there's something happening to the SuperMarraige that we haven't been clued into, it's been done to death as an idea, and not particularly well, unfortunately.