It's not more that Tony cheated, sadly he isn't the first to ever do it and that would be just between Eva and Tony to work it out how they like.
The Big deal is who he screwed over. iT's just beyond low to do that to with another man's wife especially one that you know personally. Even more so if he is a friend of yours as it has been stated that they were friends. It's plain disrespectful.
If you guys don't feel that way then I'm very glad I'm not your firend