I did ask earlier in your thread about a possible OW...too many signs that indicate there may have been one.
YOur H is trying to balance this other "fantasy" life he is living w OW w his "new family" life w Ds. And, it's an impossible task.
How did you confirm his involvement? Is it an EA? or PA? Either way is painful for you. I know first hand.
I disagree w longrun and WOULD address H introducing your Ds to OW and involving them in activities w her. I would absolutely set boundaries about this. NO OW W Ds present! You should have every right to state your feelings about this w H.
Also, as long as this affair is a "secret" it will keep and maintain the excitement for H...when he knows he's been caught, it will lose some of that for him. And guilt may set in, if it hasn't already.
I believe it is BETTER to have things out in the open...not all the dirty little details, but just what you feel you NEED to know. And, then your boundaries surrounding his time w your Ds not including HER. Sooner, than later, I say.
M- 18 T-21 S-14,11 & 10 BD 6-18-2012 (OW-EA) H moved out 11-3-2012 10-5-13 Me- I want a divorce. I want to move on w my life. 11-25-13 Jointly filed.