Ha ha this sounds so familiar. I caught my guy on a webcam website, first of all he said he was looking at stuff we could try (I had expressed an interest in it) when I caught him on it first time. Second time, it was just the homepage, I questioned him about it and he said he over heard a couple of guys at work talking about it and he decided to look it up.
Third time, he logged out but didn't close the window. I clicked back a couple of times and discovered he actually had an account, for 8 years. He was on his way to work when I called him up and practically dumped him over the phone as he wouldn't give me his password for his account. He says he has deleted it but I will never know. I've discovered facebook messages (just to note, I do NOT know his passwords, don't ask for them, and don't search his phone) but he had left facebook open on the laptop and saw he had been messaging some girl asking for photos of this girls tits. Of course I couldn't leave it there, and scrolled all the way back through his conversation with her (over 1 years worth) and discovered this had been going on for some time. This was last July. He said it was all just an inside joke, they had been friends for over 10 years and used to work with eachother.
Fast forward to November, I think this is when his sex drive started to drop. He says it is due to stress, but meanwhile mine has never been higher. I've become alot more confident in myself, and instead of even trying to keep up, nothing. I took some time off over Christmas (didn't have to) to be with him more and what I was hoping for is for us to be at it constantly, and to not be able to keep our hands off eachother. Exactly the opposite happened, we maybe had sex a few times over the festivities. It was our 2 year aniversary yesterday, and I feel less desired than ever. I can't even remember the last time he kissed me which was more than a peck. Of course I would like sex now, but I want everything else that comes along with it.
I really don't know what to suggest, as I don't know what to do with my own situation really. I've tried talking about it, he gets his act together for maybe a few days and then slips back into how he was before.
I know how you feel about him wanting to do other things other than be with you. As I say, I took off a lot of time over Christmas to be with him more and enjoy eachother's company but to be honest I would have rather have gone to work instead of feeling this way.
So to answer your question, I would say if I'm truthfully honest it would be from last July, lol!