First Official Relationship

so, I have finally gotten into my very first relationship with a very sweet guy. He's 18, a senior, while I'm 16, turning 17 in May, and a Junior. We have been dating for about 2 months now, and haven't kissed. I don't see I problem with that since we are both awekard and are taking it slow. I'm planning on having our first kiss during my prom that's coming up this next Saturday. The thing is, we are both virgins and I've been...wanting to have sex lately with him. but, I don't know how to tell him and I don't know when. I'm scared on how he would react. should I do this soon or wait a few more months after the kiss?