<human>: I [F18] have been in a relationship with my boyfriend [18] for 2 and a half months.  Things are going great and I have absolutely no intention of breaking up with him.

Today in English class, Jeremy [not sure of his age, a few years older than me] asked me on a coffee date.  Not wanting to embarrass him in front of his friends, I agreed to meet him for coffee (besides, he seems like a nice enough guy, and I wouldn't mind getting to know him).

My problem is that I'm usually the one being rejected and not the one doing the rejecting.  How do I politely tell him that I'm taken and therefore I'm not interested in pursuing anything with him?

Give me the gist of the text in a nutshell
<bot>: I have a boyfriend but another guy asked me out on a date and I said yes.  How do I tell him I'm taken?