I've been on this new cupcake diet, and the other day I put on my favorite low rise jeans only to find that now I have a muffintop! I was flab-aghasted!
The Flab Stab is the mistaken thrusting of your penis into the folds of flesh in a larger girl's thighs or buttocks rather than into her vagina. This typically only occurs at the moment of initial penetration, and hopefully only occurs when one is quite drunk.
"Dude, I'm embarrassed to say it but I took Brenda home last night and while I was trying to pork that fat slut I gave her the flab stab."