Wincest is when you screw around with your PC. Combination of
Windows, the OS, and incest, since with the amount of time you spend on your computer it's like a family member. You usually get some sort of STD from it, since the virus disabled the firewall.
It includes but is not limited to: adding RAM, updating drivers, installing new software/hardware, and actually humping the damn thing because you're so lonely.
It is also used to describe
awesome incest, but that's a swiftly aging
meme.
Wincest? This
dude is seriously still calling anything that? Get a
life dude.
OR
Oh my
god see that guy with his laptop all opened up? Total wincest, get a room dude.