If you want to see where you stand with him, in my opinion, keep standing...don't sleep with him. Refrain from any/all forms of sexual behavior, except kissing/necking.
IF he cares for you as a person, he'll understand your not wanting to do the "deed"; if he's just in it for sex, he'll leave.
It might hurt to find out that he just wants to separate you from your panties, but it's best to find out now than at some point in the future.
Hey, there are guys out there that like girls for the company and friendship...and love...not plain sex.
Good luck to you!!!!!