Yes I do, and I understand he's in the extreme minority, but there is logic in there. It's not something I would do, but I can understand the logic in "I don't want to know about it". If that person can deal with the nagging suspicion the rest of his/her life, more power to them. However, we are not robots, and I can't fathom a human being doing that. But logically, it makes sense.
Here it's rampant. It's almost a given that if you're in a relationship, one or both have already cheated. It's like an unwritten rule. It doesn't make it any less ugly, and people still have their hearts broken, but it's a cultural thing. They realize that if the partner can do it, then so can they. Also, vice versa, and I think that's why there isn't such a big deal about it. If (ha!) Berlusconi had an affair (he's a womanizer, everyone knows he does), no one would give a shit. As long as it doesn't affect the public personally, what they do in their private life is their business. Meanwhile, our entire country was up in arms about Clinton getting a hummer from some pudgy intern. It's just another cultural difference, and it's not better or worse. You just have to decide which type of person you are.
There's an old saying here: "You get three days to cry for him/her; after that, suck it up and find another."