"And now onto you and Chris. You consorted with some one who proposed having sex with you."

"Spending time with someone who proposed having sex with you isn't cheating in and of itself."

Probably we are using the words differently. I read the OP as, his girlfriend's friend actually and explicitly suggested or asked for sex. I assure you that nothing like this has ever happened to me when I was in a committed relationship and if it had, I would have reacted the way I outlined above. If you think the OP meant that Chris had signaled his availability or interest should the gf decide to make a move, I suppose you're right that that's different and perhaps more common. I've certainly gotten signals that men have found me attractive even if I was in a relationship with someone else. Whether that equates to, would have fucked me if given half the chance, I have no idea. I suspect not because they're really good guys and, you know, that would have been wrong.