He needs more pressure and more exposure yet... He will have to come clean eventually... He just needs more time.. you have only shut him out for one day...

Denial has more force in a group.. He hasn't been confronted directly yet, just a call on phone and you had apologize dfor that.. its nto a lot of force yet... time will add force on its own.. i estimated 4 - 6 weeks before he breaks down and admits something...

You need to keep him shut out for a while so he can see you are serious ... Your position is

I don't want to hear a word until you are fully honest with me about this woman.. I already saw you kissing her.. I am not stupid, i can tell when you're lying.... Lying to your children's mother about an affair.. You consider that being a good father? cheating on your kids mother and lying to her about it?

He needs to hear more lectures like that... he hasnt' gotten much.. he's HIDING yet...