[masraum]

I don't know if I would or wouldn't do it. I am pretty sure that I wouldn't, but without being in a situation that traumatic (which I think we can all agree it would be VERY difficult) I can't say for sure.

I suspect this behavior is more about a coping issue than anything else. This guy is undergoing one of the most stressful things that a person can go through, and the person that he's had for support can't. Whether it starts as a friend that he can talk to in the stressful thing and the emotion and closeness of the situation leads to other things, or the guy is stressed out and has a purely physical fling to help relieve the stress, I can see how you'd end up doing that.

Or, he could just be a total douche, but if that's the case, then he's probably always been a total douche and has probably been screwing around for years.