Dirty Graeme
That moment after you're girlfriend lays a steaming turd on your chest while you stroke your cock and you hear her husband coming, so you stand up quickly while continuing to masturbate as the turd slides down your belly on to your cock making a huge mess.
I pulled this bird last night, after taking her home and getting her to squat over me, I heard her husband coming up the stairs so I had to Dirty Graeme myself and get out of there.