-The newest member of any group will always be considered the noob until someone else joins and the title is passed down. As long as the title is used as an informal joke among group members and not maliciously, it may just be something you have to bear with until someone else joins the group.
-Role players and other gamers, in the U.S. at least, have traditionally been stigmatized by others as 'nerdy' or 'satanic'. These ascribed stereotypes often form stronger bonds among gamers in an attempt to rebuff negative attention. Your fellow gamers probably assume that by not telling your boyfriend about your hobby, you are, at least in some small part, ashamed of your participation in this hobby. They probably feel that you don't really enjoy it or want to be there with them. It would be like having a friend that you didn't want to be seen with in public.
-I'd suggest talking with the group and expressing your fears to them directly. Ask them for advice in dealing with any negative attention that you might receive. They might offer helpful advice. Additionally, it should bring you closer to the group.
-I'd also give your boyfriend the benefit of the doubt. He could be okay with it. After all, if you're spending a lot of your free time gaming with an all girl group, you're not out seeing other guys. Finally, if anyone doesn't want to hang around with you just because you like this particular hobby, they aren't, at least in my opinion, worth the effort of mainaining any sort of relationship/friendship.
