You need your space. I have been there.. Only in my case, the OW told me about it when my H broke it off with her.
I had had my suspicions too.. when I saw a charge at a nightclub for 400+ dollars overseas and when I looked up the club online, I saw a picture that the two of them posed for (crazy, huh?), but he denied it and claimed it had been one of his employees fiance.. stupid me WANTED to believe him to bad that I did and I ended up apologizing to HIM for having accused him. Looking back at that now, I feel stupid.
Take your time to process.. Ask whatever you need to ask of him. Just know what you're setting yourself up for. Ignorance is bliss.. I didn't ask but the OW sent me basically every email and IM the two of them had in their on and off 1 year affair and I will tell you that sometimes I wish I didn't know as much as I do. The mind movies are hard enough on their own without that info.
Good luck and hugs to you. I am here if you need me!
M: 32 H: 34 S:5 D: 3 D: 1 Together 11 years Married 7 Bomb: PA/EA 8/13/09 (for 1 year on and off) ILYBINILWY: 08/09
"The end of suffering happens with the end of wanting." -Laura Munson