A term used when a male stuffs his penis inside of a females anal for 5-10 seconds until female preforms a fart; then quickly the male releases the penis from the anal leaving a parachute of poop shooting from the females rectum onto the mans chest. This action can also be done without the discretion of the male.
Guy 1: So bro, how was hanging out with that Russian chick? I heard she does nasty shit...
BSDD also known as 'Back Stabbing Designated Driver' is referred to person who is set out to be the designated driver in a situation where his/her friend are already planned to get wasted that night. The 'BSDD' is known to get drunk first on purpose leaving him/her incapable to drive having him/her's friend out to be the new 'unplanned' designated driver leaving that person to stay sober for the rest of the night and missing out on loads of drunken fun him/her had planned for the weekend.
Brad: Sup, man. How was your birthday weekend? I know you've been waiting to get wasted allllllllll week!
Todd: I was sober all night. God damn Tommy ended up pulling a BSDD.