TSIF

"Thank Satan it's Friday."
A variation of "Thank God it's Friday." But for athiests.

In "Friday night" by Taylor swift, pretend one of the people screaming "TGIF" said "TSIF" instead.

Background extra #1: dude, how did you mess up the lyrics in that part?! We were all literally screaming it!

Background extra #2: Sorry dude, I just didn't wanna thank some pretentious thing that wants us to worship it, so I adjusted it to "TSIF" instead.