<human>: Can you provide a brief rundown of the text in within 3 sentences?

So let's start with how I met him. It was my freshman year and my German teacher puts me in a group with my now boyfriend (let's call him John). I developed a crush on him, but after the project was over we stopped talking... Until last year. 

 

I was hanging out with my ex and a couple of friends when they say their friend was coming by with his car and we were going to ride around with him. I get into the car, look up, and there's John sitting in the drivers seat. We hung out some, until summer we lost touch. 

  

Go to New Years my friend (let call him Bob) invites me to a party. Lo and behold him and John are step brothers. After drinking quite a bit, John starts telling me how I shouldn't be with my bf I should be with him instead, stuff along those lines. John and I started talking about being together after the party, soon enough we were a couple. 

 

Since then, he has told me how scared he is that he's going to cheat on me. I had trust issues before he told me this, now I feel paranoid constantly. I'm afraid to get any closer to him because of it. Especially with the fact that I'm still in high school and he's in college, I'm always thinking he's doing something. I know it's not healthy. But I have real feelings for a guy in a long time.. I don't know what to do... 

 

Sorry for it being so long.
<bot>: Boyfriend I have strong feelings for says he thinks he's going to cheat on me, I don't know whether I should stay or leave.