philadelphia boxcar
the act of having sex with another persons colostomy hole.
there was this old man who had surgery so that he had to use a colostomy hole in order to poop, and he would go down to the jail yard and sell his colostomy hole for 5 dollars to the inmates so that they could fuck it. the man is from Philadelphia and his colostomy hole is packed like a boxcar so that is why its called a Philadelphia boxcar.