Yeah. Years ago, I dated a fat girl. Sex was always her on bottom. Always. And, contrary to Tumblr, no, it wasn't that great.  My current gf is 110 lbs. I can throw her around. I can pick her up and we can do it standing. It's glorious. Having been there and some that, I can honestly say that there is nothing an overweight, let alone obese, girl has to redeem herself sexually by the very fact of being overweight.