Go Fuck Your Self With A Pool Noodle
And yes, we know that your self is one word; the 's' just adds length. Most people have no idea what it means so feel free to say it when you want.
Person: Well, yeah, I know what the gfys part means but wth is up with the wapn part?Gfyswapn?
Smart Person: Go fuck yourself with a pool noodle, and no, not literally.