here's what worked:
Basically, she is on top, cowgirl position. I grab her by the waist and instead of moving her up and down (vertically) I move her forward and backward (horizontally), not a lot, just like 3-5 inches or something. Your cock will be deep inside of her and her vagina will be rubbing on your crotch/lower abs. think of homer simpson choking bart simpson.
I think that it put pressure on her deep spot and her g spot at the same time (as far as I know, they are both similarly in line and require the same type of stimulation). she loved it and came all over me. I have done this with one other girl, no ejaculation but much reported pleasure.
here is a video which explains both g spot and deep spot stimulation using fingers. you can see how the sex position I discovered mimics this:
try this and report back to me.