Everybody has to play it how they see fit, based on their own situation. I personally told my wife -- who was under the delusion that I was going to still be "best friends" with her -- that I would NOT even be a GOOD friend to her if she decided to end our marriage this way (by having an affair, lying about it, and refusing to work on our marriage). If, however, she ended her affair, and truly worked on us (including counseling), and if things didn't work out, then yes, I thought we would always remain friends.
Friends just don't do that (lie and cheat) to each other.
