when a guy pisses in a chicks tampon and it inflates to a disgusting, soft yellow mass, usually happens in the act of banging a chick with her periods and pissing inside her.
"yeah i went to slam my bitch but she had her rags so i gave her a yellow marshmellow instead
by james November 17, 2003
A toilet paper roll that has been soaked with urine. The roll will plump up like a marshmellow and turn yellow.
As revenge he left them a yellow marshmellow.
by Bushki007 June 28, 2013