The act of finally letting out flatulance after having sex in a monogamous relationship. Singlepeople may find this act disgusting, but married folk consider it mildly flattering that their partner held their gas long enough to engage in intercourse. Married people know that gaseous discharges is a sure way to let their significant other know that they have zero interest in sex. Holding it in until after the sex act lets the spouse know that they were both horny and gassy.
I treated my wife to a romantic evening of flowers, dinner, and wine. I found out later she wasn't feeling very well, but she did her part. After we went at it like horny teenagers, she let out a huge post coital fart. All I could do was laugh.
The flatulence that ensues after having relaxing sex. It's the fart that seems like you areripping space time due to the extreme relaxation of your sphincter.
Also the reason we aren't getting the deposit on our apartment back.
"Hey Dave I'm sorry to say we aren't getting our deposit back"
"Why's that Brian"
"It's was the post-coital flatulence"
"Damn it Brian your ass is foul"