My Pants Have Turned on Me...

I was going to the bathroom and only had one free hand to pull up my nifty pants. When something bites my hand. I looked at my thumb and it was missing a small chunk of skin and bleeding. Why?

I didn't see anything on my pants so I looked. First I thought one of my studs came loose and was poking through my pants. So I loosened my belt and the metal disappeared. But none of the spikes were loose/pointy.

What happened?

Well, I used scissors to pull out this metal thing.

It was an unbent staple. ________ <This long.

Gosh. My pants tried to kill me.