Massiv Fagget!
Not to be confused with Massive Faggot.
The term Massiv Fagget refers to someone who disappoints his/her friends. Almost always used as a joke to show your disappointment.

Note: Always hold the M when saying this phrase.
eg. MMmmmmmmmassiv fagget!
Friend 1: Do you wanna go do something today with Jimmy and I?

Friend 2: Nah sorry, I'm kinda tired.

Friend 1: Ohhh, mmmmassiv fagget!

Friend 2: I know, I know, I'm sorry. We'll do something tomorrow.