Would I be wrong?

My friend wants to go out to lunch sometime next week, as friends do, but it's a guy! We've only known each other about 3 months so our friendship is still new & interesting which I think is the best phase. The only issue is my bf thinks all guys that talk to me are trying to get with me although I assure him otherwise. Many of the friends I had have gone separate ways so currently I don't really have any friends and I find myself wanting to talk to other people besides my bf sometimes (strictly as friends of course). Would I be wrong for going to lunch with him?

Btw my bf doesn't try to control me as I've had guy friends in the past but I can tell it makes him a bit uneasy if he knows I'm hanging out with another guy but I don't think it's fair for him to be able to hang out with girl friends & not grant me the same.

What's you guys opinions?