1: A more elegant term used in place of "Suck my cock".
2: The way an angry Bostonian man, one that probably doesn't respect women, would ask for fellatio.
Cack sack is when two people are dancing and one of the people is saying “YIPPEE” and then someone in the party drops a pie and the pie land on the face of the YIPEE MAN you can say, he had a cacksack of a day