After some 60 years of sex research, science-type people are unable to definitively locate a "G-spot." (did you know it's named after a dead German gynecologist? think about THAT during your next sexy times) They're not saying that any and all stimulation is all mental or faked though (except for your girlfriend, OHHHH BURRRRRN). Rather, pleasurable sensation comes from several different structures converging, and there's not a special, particular erogenous gland tucked away in there. I'm sure the test subjects were very happy to assist with studying orgasms.

mmmmmmmmm YES YES YES OH GOD OH GOD OHHHHHHHHHHHHHHHhhhhhhhh

"Through sex alone?" What did the other guys have to do? Feed her nachos and ice cream? And was that "sex alone" or "sexting alone?"

But if she makes a sound like an accordion, you're probably doing it wrong.