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1.
abv. for "This is it for me". Expression made by couples once they find that significant other they want to spend their life with. Being in love with someone and knowing it for sure, without pretending.
My boo's text read TIIFM. I'm in love, I'm in love and I don't care if the world knows it!

TIIFM bro/girl, this is the girl/boy of my dreams.
by Mr. pinguino November 25, 2010