How do you get over your husbands affair? Should i talk too his mistress or move on?

[Distraught Wife!]

I have taken him back even though he wont tell me the truth. He says he only kissed her but i have seen msn convos between them which tells me there was a lot more too it ( including g sex in MY bed!) I feel as though i need too know it all before i can cope because he lied too me for months and so did his mum! I sat with his mum while she knew he was in a hotel room with her!!!!!!!!!

WHAT DO I DO!!!!!!!!!!!!!!!