It is hard for some people to grasp not having access to your own wife's pussy. The fact is, it was never that great having you penetrate her in the first place. That is why she quickly cuckolded you when you presented her with the opportunity. Now that she has a boyfriend, she gets regularly fucked by him. Of course it is better sex, that is what you and your wife sought out. You still are her best-friend, you have your house, kids and life together. You cuddle and kiss and are intimate. Her pussy now is just for other men only and that is arousing for both of you.
You wish your wife hadn't talked about something so private -- so intimate -- and so humiliating -- with anyone else, and you're surprised that she did, but like she said -- she usually tells her best friend everything. But now you don't know how you can face Karen, knowing that Karen knows about your sexual inadequacy problem, and especially because Karen knows that your wife is going to start cuckolding you.