I am sorry to bust your bubble and I don't wish to sound harsh, but I used to think that my husband would never need, let alone want sex from someone else, he had access to all the sex anyone could possibly want at home. Was I wrong, because I don't care what excuses they use, I can guarantee that whether it is porn, internet date sites, (just a bit of harmless fun according to them)chatlines, phone sex, internet sex whatever, it will eventually turn into physical sex with someone else at some time. It gets to the point where what they are doing just isn't enough. You really need to understand one thing, if it feels wrong to you then it is wrong for you. If it doesn't then just remember this one piece of advice, keep your eyes OPEN. I wish you luck and hope that he never shatters your heart like mine has been, and that you never lose your faith and trust in other people because of it.
good luck