...or let your kids watch it... Idiot

OUCH!
(but I think it is fake)

What a doofus, GF thinks he faked it. If it's true, his hand won't be quite right for a long time. Lots of small tendons in your hands and if you cut one it's not good.

Could be fake, who knows. But stupid it is. I have know guys who would have tried that stunt, right after saying "Y'all watch this," and "hold my beer"...

Concur, could be faked. But stupid.

It's faked.

It's probably a twist on the Mouse Trap trick that Penn and Teller did in which the setup is that the magician can tell which of the mousetraps are safe by feeling a knot on the underside of the lazy susan.

In the linked video, the lazy susan is most likely marked around the edge with something the magician can feel. When he slides his finger around the edge to stop the lazy susan, he can stop it where he wants or perhaps feel if it's stopped in the correct location. Notice he gives the lazy susan another quarter turn before he smacks the cup to make sure the one he wanted to crush was facing the camera.

The lazy susan could be visibly marked as well. The compression on the video is bad enough to hide most anything.

Also, if you read the description on the right it says, "Make Sure to Check out Brian's show "Scam School" at revision3.com". Probably a dead give away. LOL

Could be.

I remember seeing a guy do that nail trick when I was in 'bout third grade. That was back in the days you had to walk ten miles to school, in the snow, uphill both ways, after milking the cows and shoeing the hosses, wearing only a worn out pair of bib overalls and boondockers with no soles...

Fake. Blood shows up too soon after penetration. The guy needs to study wound characteristics more if he wants to make it genuine looking. There are other clues as well.

Still... a good candidate for natural selection... maybe he shouldn't fake it?