There is no way possble to know if someone ha had sex before without them telling you. Why does it matter what he did in the past though? I dont see the reason in knowing or not, its the past and you need to focus on the two of you and the present.
Unless you are highly experienced it will remain a mysetery. Might as well drop the subject. You asked...he gave an answer...you're going to have to accept it.
You can really only trust his word on if he's had sex or not.
