When the person receiving a blumpkin drops a huge turd and the person giving the blumpkin gets a huge splash of shit water on the underside of their chin; When the person giving a blumpkin gets water splashed on their face from a dropping or exploding shit.
Kerplunk + Blumpkin = Kerblumpkin
I need to wash this shit water off my face because my boyfriend gave me a gnarly kerblumpkin.
Getting a blowjob/head while standing over the toilet vomiting. Not as regrettable as the variation blumpkin, and easier to accomplish
After a few too many drinks, nausea set in and while vomiting in the bathroom I pulled my pants down to start getting some kerblumpkin. When she was done she told me she loves me.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.