From fap + -tastic.
faptastic (comparative more faptastic, superlative most faptastic)
- (vulgar, slang) fantastic in a way that stimulates one's libido
2003 August 8, maddman, “Re: wow check out that ugly mug!”, in alt.support.shyness[1] (Usenet):She's faptastic, no doubt about it. But that's a professional photo, with perfect lighting and expert makeup and retouched in photoshop. Models are not that hot in real life.
2008 April 3, rct, “Re: Where's Odin & polcock & Geoff....and Feder?”, in rec.music.makers.guitar[2] (Usenet):> I expect to see some FL spring break pics soon. And not of
> the band.
Sounds faptastic!
2014 January 27, Steve F., “Re: OT. OK All You Junk Science Worshipers”, in alt.home.repair[3] (Usenet):> Lots of dog-ears, spooge stains, and other schmutz, though.
LOL! I *was* going to add that he thought the book was faptastic.