Jim- Dude...isn't that kinda weird?
Steve- Nah man, it'll be awesome.
30 Minutes later.
Steve- Isn't this great?!
Jim- I think i'm gonna be sick...TISFUS bro.
Often varied to "tismu", "tirfu", or "tisfmu" meaning "that is so messed up", "that is really fucked up" or "that is so fucking messed up" respectively.
Dude: Dude, my name is Dude. Did you ever notice that?
Jimbo: ...no...dude, tisfu!!