Next question :

How is your MIL in regards to supporting your H's behaviour NOW that you KNOW its a sexual affair? What about other relatives?

List each family member and where they stand on this... I would get a spreadhseet togehter with all contact names, numbers, emails etc... find out who your friends are and make sure they are ALL in the loop of what's going on... You want to beat your H to the punch on this one... He's going to grease the wheels before you if he can..

HIDE all your info on your PC so he can't snoop... he will snoop

I am worried his mother is going to enable him even during a sexual affair... If you stay at the family home I really don't imagine his mtoher is giong to refuse him entry into the home you are in since its his parents home... You want a safe place.. and I don't know if his parents place is that place if they can't take a hard stand on what he's doing and refuse him...

What you want them to tell him is something like :

"I am embarassed at what you are doing right now. I am humilated and sad. I don't want you in our home or near either of us until you stop what you are doing and come to your senses... I will NEVER ACCEPT OW in our home or in our family, she is a disgrace... and our DIL is ALWAYS welcome here... she's the oNLY ONE protecting this marriage and our grand daughter"

SOmething like that.. if she can't folloow through on somethin glike that, you dont want to live with your in laws