I a guy, and I've had a number of hookups, I wouldn't ever even question someone asking me to wear a condom (though, to be fair, I'd choose to wear one also). You don't know the other person. Unless you just really get the sense you can trust them, it could all be a lie. Your boundaries aren't a debate. Honestly, if I were you, I would have kicked them out. If they're questioning that boundary I wouldn't want to find out where it ends.