Well.. this seems like as good a first post as any!
Most women can't orgasm from G-spot stimulation alone - so don't feel bad! I can't reach the big O without clit stimulation, no matter how good it feels. I can get to the edge, but I need my magic button touched to push me over.
Having my G-spot massaged does give me a MUCH stronger orgasm when I finally do reach it, though. When your boy is playing around down there, get him to massage it in a "come hither" motion with one or two of his fingers. He needs to apply a decent amount of pressure (once you've gotten past the peeing sensation). Once you're edging, have him pleasure your clit (tongue, finger, or otherwise) in rhythm with his finger... uh, thrusts, and you should experience an orgasm that i can only describe as explosive.
I get *very* sensitive after an orgasm as strong as those, though, so make sure he goes easy on you once you've come down from the high.