When you are going down in your brother and you pull your cock out of him and shoot your load on your baby brothers chest while making intense eye contact with your dad.
Me and my family had a dirtyGreyson the other day.
A Dirty Greyson occurs when you inject Boar Semen into both of your ears, let it crust, and then proceed to have your sexual partner scrape the semen crust out of your ear while grunting to that of a wild boar.
Duuuuuude, I can still feel the crust in my ears from that sick Dirty Greyson we pulled last night
Similar to the Male octopus, the Male will RIP off its penis and throw it to the female. She puts it in the freezer to make it hard and then fucks herself.