Geez, you guys are too fond of monogamy. What, god is going to spank you in the ass f you have an affar? I will not try to convince you, i guess the monogamy myth is too deeply buried nto you guys.
I've no problems with affairs, i even convinced once to my gf to had one, and our relationship improved. She felt liberated. I do endorse an affair, under very special circumstances.