I don't know where to begin. I have been involved with a man who over time I have begun to wonder whether he is a sex addict. I knew him a long time ago and we reconnected online. Initially, I was turned on by his hot pursuit, but over the course of the last eight or so months, I have learned details that, when added together, seem to paint a picture of someone struggling with an addiction, and not just a kinky very sexual guy. But I can't be sure. I feel like I am a lobster in a pot of slowly boiling water, and haven't noticed the heat getting hotter.

The most recent thing, as of yesterday, is that he asked me about what makes women make a mess of their panties. He wanted to know details. Like if she was "rubbing her *****" to make them wet. I asked what panties he was looking at. He stalled. He eventually wrote me that he went into his girlfriend's daughter's room, who is 18 according to him, and saw that there were a pair of her panties on the floor. He said he looked at them and saw that they were a mess, according to him. Now, mind you, this is what he told me. I can guarantee that he did more than just look at them. I know he has a panty fetish, and honestly, I thought it was kind of kinky/hot for a while-- but this crosses all kinds of lines in my head-- but am I overreacting-- was it just curiosity? Just thoughts? I am really open to fetishes, kink and role-playing. But there is a big divide in my head between fantasy and reality. I responded kind of neutrally because I was so shocked, and got a message from him this morning saying that he felt guilty for looking. He has never admitted guilt for anything before, and I am not sure I believe it. Or maybe he does feel guilty and in that case, I am unsure how to respond. I don't want to condone the behavior, and I don't want to shame him. I feel gagged, honestly and am still in shock. Plus, I am looking back at all of the pieces of the puzzle... the picture is dizzying.

1. After 6 months, I asked if he had a girlfriend, because some things started not adding up. He said yes.
2. So, he has a girlfriend and is essentially cheating on her.
3. He watches couples have sex online, live. People he knows. He's asked me to join in and watch with him. I have not.
4. He has forwarded me messages where he is organizing an affair when he is traveling, and trying to set up another.
5. He asked if he could meet my best friend (and sleep with her, so that she could tell me all about how good he was in bed)
6. He sends panties that he has ejaculated in to women he has met online.
7. Did I mention that he has a girlfriend? I asked if his girlfriend likes that he has sexy chats with women online. He said no.
8. He cheated on his ex-wife extensively, with at least two women. Undoubtedly had online affairs with more.
9. He has had. or currently has, these online relationships he has told me about. I can count at least five. And those are just what he has told me about.
10. He talks about sex constantly. Or always steers the conversation there.
11. He consumes a large quantity of porn.
12. He flirts with women in online deviant forums, such as people posting selfies of themselves on the toilet, or an erotic art group.

Actually, writing this out like this is helping me-- to see it all.

I just feel like I have been in a fog, because it has been a slow reveal and always in a way where I feel like I am trying to be accepting. I realize that this makes me look weak or lame.

This thing yesterday though, with his girlfriend's daughter's panties--

How do I respond? Or is no response the best response?

I am realizing I have thought of him as a flirty friend, but I think he must think of me as something else. What, I do not know. I feel sick to think of all of this.