How do I ask??...

So I've been with my fiance for 6 years. Lately since I got off birth control my sex drive has been insane! And even though I love the sex we have I've been really curious and want to have a vaginal orgasm (never have one before ) but I don't know how to tell him or ask him to help me...I've never found my g spot and I've tried on my own but I cant...any advice?