While having anal sex you cum inside of her ass. This sprouts from the childrens book James and the giant Peach where James COMES inside the giant peach. Its a play on words where Peach represents the ass and coming is self explanatory.
So me and her were doing anal and I totally James'd her Giant Peach! (Jamesing the Giant Peach)
by James of the Giant Peach September 20, 2009