To render one's anus or vagina in a graphical state of distress, as a result of a particularly violent bowel movement or penetrative intercourse.
The description comes from the similar appearance to the ripped edges of a windsock (an item of metrological equipment used to establish wind speed/direction) as used at airports/flying schools, etc., which have become tattered as a result of excessive weather conditions.
"God, that curry last night was awesome - my arse puckered starrusty sheriff's badgechocolate tea towel holder this morning was like a tattered windsock"
"He was hung like a horse; my twat vadgegrowleryeti's welly looked like a tattered windsock afterwards"
A vagina so loose that the term, throwing a hot dog down a hallway, doesn't do it justice. In fact, the vagina is so loose that normal cycle sports, wind surfing, or any activity which involves motion.... creates a. windsock effect on the vagina.
Lucy's mom went motorcyling and we saw her windsock vagina flapping in the wind.