Ash: I want your charmander, wttf it for my bulbasaur?
Kid: No..
What The Titty Fuck- while not wanting to sound lame by saying WTF or wanting to be too bold and say WTAF (What The Ass Fuck)
Guy 1: I just pooped in a cup and left in in your room.
Guy2: WTTF man!
Welcome to the forums. Used when you want to greet a newbie and confuse them at the same time. (It looks like WTF.)
New Guy: Hey guys, I am new here, so here is my introduction!
Old Chap: WTTF
Classified ad: WTTF - a mating pair of Pygmy Macaroni Penguins. Your choice of my little brother, big sister, or my dad's 1982 Datsun.