I'm still not sure it was "just sex." I have the same issue. It was sex, but, if he has someone else (as I know my H does), then he could have had "just sex" with that someone else. Either way, you have to focus on you. I know how hard it is to have them be sooooo distant, but I think it's good for you. It removes the temptation to argue about anything or try to ask questions about their lives, etc.
The hardest thing for me is knowing that there's nothing I can do at this point to make H come home. He has to do that himself. So, all I can do is work on being better. If he notices at some point in the future, great! If I get over him while I'm doing that, well, so be it!
I also had someone say to me that other day that my interactions with H seem to all be about trying to have a better R with him. The problem with that is that he doesn't want an R at all right now...so, even a better one is not appealing to him!
You've done well not calling...just hang in there! Get busy doing something for you, and don't worry about the sex or the possibility of an OW, etc. You can only control you!
Take care! Amy
Me 39 H 36 S 7 S 4 T 15 M 12 H out 8/1/08 OW confirmed 8/6/08 D final on 6/12/09...I'm doing good!