when you go to someone's house (preferably someone you don't like too much) and you take the top part off of the toilet and take a dump in the tank. from then on until the owner of the toilet discovers the dump, the water that comes out when you flush it will be a wonderful "rusty" brown shade.
"dude i 'rustic waterfalled' that broads house after i found out she cheated on me. the toilet still drains turd water."
when you are bangin a girl/guy in the dark and you get off and tell them you are going to the bathroom. meantime your buddy is waiting to trade places with you, and your buddy preceeds to go into the room wher the girl/guy was left in the dark and finishes the job. works best if the second person doesn't talk to avoid comprimising the situation.
a.k.a. double dippin, taggin out, or calling the bullpen
dude, that dark swap we pulled last night was brilliant. she never knew it wasn't you when i was bangin her.
when you get a boner in public and the only thing you can do with it is push it upwards and hope your waistband/belt can minimize the tent you are pitching. not sure where the duck part comes in, only scholars maintain the translation.
i was playing basketball and got one of those random boners. i had to duck tuck that thing before everyone could see it.