Grandma McFlurry

When three or more sperm donors ejaculate into the Urn of a deceased grandma.

Agnes was such a cumslut, the boys and I gave her a Grandma McFlurry to let her ashes rest as she did.

Grandmas McFlurry

The act of ejaculating inside an elderly woman's anus then proceeding to pull your penis out and urinate in the elderly anus.

Yo bro remember Lews grandma from the club? I totally gave her a Grandmas McFlurry last night!