A guy wants to have with me, i'm not sure its the best idea...?

So, I've been talking to this guy a lot on the phone, we have mutual friends, and we started talking because he's coming to the state I am for grad school. He lives really far away, so we've met once and immediately clicked. We started talking on the phone a lot, and he straight up told me he wanted to ..ahem.." me". I feel the same way too MOST OF THE TIME. But there are certain things that are stopping me from having w/him...because I decided to take a vow of abstinence after I had an STD scare..but I want himmmm kinda badly! Plus, I know we're not gona work out as a couple (as in serious couple), just good friends, and casual friendly is something I NO LONGER do. He thinks since I've done it in the past, I will do it now...How should I prepare myself before he comes here, in order to resist him?! He's pretty sure about us having ! I must resist though, I must!!