Backdoor blackout
A backdoor blackout is defined as an anal sex encounter with your partner followed by short term memory loss due to copious amounts of alcohol and or illicit street drugs.
Gregory: "Last night I had sex with my partner in the ass and dont remember. I was pretty high and intoxicated. Is there a name for that?
Joe:
"Duh man, its called a backdoor blackout.
Joe:
"Duh man, its called a backdoor blackout.