Donut friend

When two individuals engage in a reverse human centipede, aligning their anuses - to causing a somewhat unobservable eclipse of the buttholes.

Donut friendships are usually initiated between inebriated friends, but the act has some has some obvious sexual connotations.

A study (citation needed), declares that those who partake in a donut friendship are said to form closer bonds than even the most intimate human relationships.

"My donut friend Paul is coming over tonight for dinner."
"Would you like me to leave?"
"No it's ok, we'll go to a different room to reunite. We have a lot to catchup on."