Clopnopin' is the act of getting high on horse tranquilizers (such as Klonopin) and then masturbating to pornography of the My Little Pony: Friendship Is Magic series.
"I caught my friend Marc Clopnopin' in his room the other day. Needless to say, I don't talk about horses with him anymore."
by Goatse.gov July 21, 2020