wopen tach is the act of viewing any sort or pornographic material or saying something containing sexual innuendos.
"BRO WHAT YOU SEEING AH?? THE WOPEN TACH AND TACH AND TACH AND TACH AH???"
"wow bro you doing the wopen tach ah?"
Crikey Clive, you need the number to my barber, that’s a right Beefer tache