SIS is an acronym popularized by the Canadian music artist Peaches in her song "Fuck The Pain Away" and it means "Stay in School".
Person 1: Remember the teachings of Peaches: "S-I-S, IUD, Stay in School 'cause it's the best"
Pesron 2: I love Peaches and, you know what, school is really the best!
Pesron 2: I love Peaches and, you know what, school is really the best!
by Max the Mad Cat May 26, 2024
Get the S-I-Smug. by TobiWanKenobi April 17, 2020
Get the Operation Smug. by Beesey Churger December 30, 2024
Get the Digs (d^S-)mug. by PineappleJuice May 14, 2015
Get the Love for one's parent(s)mug. 

