You wait as long you can stand it. The hard part is you deciding if you want to divorce him because of the affair. It's up to you.
If you want to save your marriage, and heal this thing, let them ride out the affair, it will, most probably end.
Don't pressure him, her shit will start to stink soon enough ;-)
Either way, Get a Life. Blossom.
It'll make you stronger.
If he's gone for good, you'll be at the top of your game. To live in forgiveness and self-repect is the only way to recover. It'll help your children more than if you are pathetic heart-broken wreck. If he wants to leave, you can't stop him. And the effect on the children is un-avoidable, but, it'll be on his head. They don't need a daddy who is unrepentant adulterer. You have the advantage of probably getting complete custody.
If he decides to come back, guess what, YOU get to choose if you want him back and you will be doing so, not out of desperation, but out of strength and power. And you may say no to him. Or you may say yes to him.
The game isn't over. Your power is growing daily, his power shrinking daily. He's done the worst he can -- he's fucked another woman and is leaving you for her. He's hurt two families. He's played his hand. What else can he do? His power over you is over. He's done his worst. He's got nothing else. The OW will start to grate on his nerves. She's only going to start to look less and less attractive to him. You, on the other hand, are becomnig a more luminous, sexy, interesting woman. They are the ones who are stuck. They have to deal with bills, visitation, guilt, disillusionment, boredom, bathroom smells. They are going to become the boring couple. You are the one with the options. Your interactions with him will make him curious and interested. You, my dear, get to be the other woman. You may be able to seduce him away from her. Or you may not, but truth be told, you will be sooooo hot, soooo interesting, so self-possessed, that it won't really matter to you if he wants to come back or not, because you choose what and who you want.
