A variation on the standard blumpkin. Instead of receiving a blow job on the toilet, the lucky recipient remains standing and poops like a horse.
"So this crazy drunk girl told me she wanted to give me a blumpkin last night. But the line to the bathroom was way too long. So I dropped my pants, stuck my dick in her mouth, and took a crap on the floor like a horse. Who knew that equestrian blumpkins weren’t allowed in Chucky Cheese’s?"