After my wife died, my widowed mother in law used to let me pump her ass like this. It was incredible, when I would shove it all the way in, she'd piss all over my balls. She'd have to mop the floor afterwards! I loved watching her clean up the mess we made, she'd sing and dance while she did it. I was too thick for her pussy, so she actually told me to "put it in her behind". I loved to hear her moan like this, it really made me pump her harder! Excellent.