<human>: Condense the text into a few key points

This story starts about a month ago, whilst I was perusing craigslist for a cas encounter. I met a guy we'll call "Bob" and I have been having sex with him ever since. He told me he had a girlfriend and they had an open relationship.

But he's been acting weird lately. First, he says things like "Don't say anything, it's my girlfriend" and will answer the phone. I asked him about this and he said they have an open relationship but don't discuss it with each other. Hmm.

Lately we have been cuddling and he has been sending me some vulnerable/emotional texts about how I give him more affection and love than his "real girlfriend" (he actually said that). The other day he said that they were fighting a lot, she never comes home, and he was thinking about a relationship with me. 

I'm really confused. The sex is amazing and I think the sex is clouding my judgment. I have a feeling he's not being honest about the open relationship. I don't know what a relationship with him would look like. I don't even really know him.

But today he didn't text me, and that felt shitty. 

So far it's just been me and him having sex in my apartment. Nothing else.
<bot>: I'm a not-so-unwitting side chick. I'm concerned that I'm letting lust get in the way of my brain's functioning.