Masturbation is interesting only because it's everything about sex that doesn't matter. It's all the physical pleasure and release that I can going to get out of a sex act, but it lasts ten minutes and means nothing. I don't come out of it happy, or affectionate, or laughing. Just sleepy and suddenly disinterested in whatever I was using as porn. (I've actually thrown good porn away during that "Now this is boring and slightly disgusting to me!" post-orgasm time. Very stupid.)
And for all my near-compulsive sexual explorations with partners, I masturbate in exactly the same way I did when I was twelve years old. Lying face down on a mattress, left hand cupped over clitoris, right hand on left breast, thrust hips against hand until porn becomes boring. It only works that one way. I can't do it sitting up, I can't do it on my back, I can't do it with my right hand.
So there is a physical difference between masturbation and sex. A guy can get me off in near to any position and with a wide variety of techniques. And frankly, even if I don't like him it still feels better. Sex and selfsex are different things for reasons that have nothing to do with fuzzy emotions, they have to do with the difference between a quiet sigh into my pillow and a fullthroated scream over his shoulder. I don't know why.
I just wish it worked the same way for guys. Obviously they do get something out of it, at least visually and mentally, but I've had a few tell me that getting their dick worked feels almost the same no matter what's doing it.
Male readers, please tell me "WHAT THE HELL THAT'S TOTALLY NOT TRUE" because otherwise I'll feel so sad for men.