The most logical explanation of the whole "Anderson Cooper cheating boyfriend" situation -- one many of us figured was the case -- via Gatecrasher:
ANDERSON COOPER could be upset about the photographs of longtime boyfriend Ben Maisani smooching another dude — but not for the reasons you may think. A source familiar with the situation tells us the couple of more than three years have an “open relationship” and what would upset Cooper “more than anything” about the photos of the owner of city clubs Eastern Bloc and Bedlam kissing another man in an NYC park would simply be their existence. “The pictures are what’s making it a big deal,” says the insider. A spokesman for Cooper declined to comment.
My guess is that Anderson didn't think the public would accept his being gay AND in an open relationship, so was caught off-guard when Ben got spotted by the paparazzi. Anderson probably doesn't mind that the public thinks he and Ben have broken up over the "betrayal," when in fact they have been seen together since the story broke. A friend of mine says Ben has a profile on Scuff in which he describes himself as a "bar owner," so I'm guessing AC makes him cool it ... at least for a while.