I don't understand him at all.

My boyfriend and I have been together 4 months. We have a great deal in common and have a great time goofing around together, but lately things have changed.

First, it has started with a sharp decrease in his sex drive. When things began we would have sex at least a few times weekly. Now, sometimes we go entire weeks without, though our time spent together has not changed. He seems less affectionate. I would use distant as a good word to describe things. He seems uninterested and uncaring a lot of the time, though will insist he loves me. He claims he is still very attracted to me physically, so I'm not understanding the lack of passion and intimacy. I've confronted him about it, asking if he feels our relationship is going in the right direction, and he denies a problem and tells me that things are fine.

Secondly, he frequently accuses me of cheating. When I leave the room, he will scour my phone and laptop for anything he can find. He has most of my passwords at his disposal (per his request) and vice versa. He's asked me outright if I'm cheating, and he's also gone as far as to accuse my male friends of having feelings for me. I've told him no. I have not been with anyone else nor have I so much as flirted since things had begun with us. His constant accusations are offensive and insulting. I've noticed he deletes messages from his myspace inbox, and has also deleted texts from him phone (though I have not checked in weeks... seeing as I'm not the jealous type). The messages were from his ex and one of his female friends. I worry because up until recently he was still speaking to his ex. She would call asking for rides home from the bar, or for him to take their dog for the weekend, or to discuss her personal affairs with him. I found that over the past couple months, he'd sent her numerous photos of them together, but claims he was doing this to empty his phone. I've trusted him and have assumed this stuff was harmless, but I am set off by his recent behavior.

What do you think his deal is?

Sounds like he's trying to get you to end things in an ass-backwards, passive aggressive way. If a guy still cared for you and was INTO you, he'd show it. He'd be affectionate, he'd be an active participant in your relationship.

His sudden distance in conjunction with his conversing with his ex and accusing you of cheating all point to bad things. They say people who are cheating or lying tend to cast the blame in the other direction in attempt to divert the person from figuring out what's really going on. i.e. he could be cheating, and accuses you so that you won't suspect him of cheating.

Also, no one should have access to another's personal account, password, e-mails, whatever. You both clearly have trust issues if you're checking up on one another. Each person in a relationship deserves to have their own measure of privacy. This involves trusting that person, but from what it sounds like, you really shouldn't be trusting him.

His shady behavior is only one of the reasons you either need to sit down and issue an ultimatum, or just break it off altogether. This drama is only going to escalate further so long as you enable it.