Once shame on you but twice shame on me?

I have been married for three years and we lived together five in all. In our second year together I caught my now husband looking at behind my back. After a long confrontation and many nights of arguing I got him to understand my side of the whole situation. I said either it or me. I understand that most of society doesn't see a problem with it but for me personally I find it to be a third, fourth, or fifth woman in my relationship. He said he would stop and three years ped. Presently I have found sites with embedded, encoded, redirected, and basically hidden sites, innuendos, or videos on cached pages in our computer. He adamantly denies it and because I am not the smartest with computers I cannot pinpoint an exact answer. He claims he has been key-logged or even hacked. We are on a wireless router but............... I have found hundreds. He has said no them belonging to him for the last 4 months daily. So lost. Want to believe but also don't want to be the fool twice. I am already untrustworthy so not sure if I am making a mountain out of a mole hill. He also is being deployed for 5 months with the Air Force and this just adds more to my dilemma. He says he is not allowed to access overseas but I have seen portals. OF COURSE! None leads to a definitive answer but there is past history and some leads to his facebook, yahoo, or gmail. He claims there not his and maybe it's because he stays logged into the sites so of course it would be under his name. So confused. Need a fresh view.