Red flags

Even before I knew about his addiction I felt like at times something didn't feel right. I ignored my gut and blamed my inner alarm on having dated an alcoholic/drug addict before him. I now call the behavior of ignoring myself as being codependent.

I "believed" him to keep the peace despite the fact that red flags were waving all around.
My first red flag came early on in our dating. He always seemed a little distant. I told my therapist at the time who told me that it was just because I described him as being an introvert when all my previous boyfriends were charismatic extroverts (boy was she wrong and I stopped seeing her shortly after). With the first few months I would come to meet his alter ego "addiction". When trying to make plans he would get irritable out of no where. I now understand that is because he had rationed his time between me and addiction...and I was overstepping. He would often ask me what my plans were for the upcoming week so he could schedule accordingly and since I'd be busy when he was acting out he didn't really have anything to explain.
Within the first few times that we have been intimate I asked him if he had any fetishes (an ex had a weird foot fetish) and what type of pornography he watched. I'm still not exactly sure what drove me to ask those questions except that he seemed to be "experienced" and that sex sometimes felt "staged". He kind of blew off my question as if it freaked him out that I would ask. another thing that happened to early on was that he had difficulty getting an erection. I assumed he was just nervous but I now know that is common with addicts because they are conditioned to watching pornography.
After dating for 8 months and still not having had the "are we official" talk...I sprung it on him one day. I told him that I was really starting to feel deep feelings and I needed to know where it was going before I continued seeing him. He said he "just wanted to have fun and he didn't want drama". I told him that I also "didn't want drama, but that I couldn't just be fun". He said he understood and I could see him wrestling with this is his mind. I told him that was fine if it's not what he wanted but I couldn't keep seeing him. He the told me he wanted to be with me.
I can see now that he knew his addiction would be a problem, but he also didn't want to give me up. While I didn't know at the time, I was really the first woman he had a "long term relationship" with and the only one which involved a sexual relationship. So it makes sense that the status of the relationship never really came up before. Since he had little dating experience and very short lasting relationships, he had never had this conversation before.
A few times while I was at his place I saw a messenger window open. When I questioned him on it (since he had no social networking profiles), he said he was trading music files. Being that he is into underground music and he said it without hesitation I believed him. On one occasion I'm not sure why but his messenger chatting struck a cord with me. I told him "I don't know what you are doing but it doesn't feel right and I'm not here to spend time with you while you chat online". He immediately apologized told me I was right and shut off the computer.
On another occasion while at his house I could have sworn I saw the personals link on Craigslist and for a split second a woman's photo. I think he realized I noticed and shut off the computer.
Several times I'd leave his room and when opening the door to come back in I'd notice he was closing out windows. So while I assumed he was looking at pornography, but since we had a very active sex life I didn't see it as a problem.
Besides these red flags there were the ones that popped up during sex. One of our first times being "intimate" I tried to make eye contact and he actually clenched his eyes shut. (I know now it's  because he was terrified of actually having a real intimate connection because he didn't feel worthy). Most other times during sex, he would just trail off mentally in fantasy and disconnect emotionally.