The act of:
Step 1: Secretly spitting down a sexual partners butt crack.
Step 2: Insert penis or substitute without permission.
Step 3: Hold on.
Step 4: Psychological Factor: Reference having sex with the partner's friend or sibling.
I am going to have to do some monkey dunking since tonight's the night and my girl needs to be taught a lesson.
An act of having sex, whether it be intercourse or any other sexual contact, underneath covers, with other people in the presence of the situation.
Guy 1: "Man look I think they are having sex under there"
Guy 2:"Yeah, they are monkey dunking hardcore"