The flatulence that ensues after having relaxing sex. It's the fart that seems like you are ripping space time due to the extreme relaxation of your sphincter.
The fart you hear from your parents bed room.

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"
by The Farterman August 25, 2011
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