Can I be with a 21 year, and I am 16 years old?

I am 16 years old. I like this guy whom is 21 years old. And he likes me too. I am still getting to know him, and not rush into things. Do you think there is any what ifs for us to be together, and him not getting into any type of judicial issues? For example if we don't have '' or anything like that? P.s. specially if I can prove while I am with him that I am still a virgin?