I have a hole in my pajama bottoms. It's in the crotch. And I have no idea how it got there. I don't often wear them to bed, so creating it while playing with myself in my sleep is a little bit of an unlikely scenario... I don't work out in them, so I couldn't have split the seam whilst doing doggy kicks or anything...
My best guess is they were cheaply sewn and through washing them they have torn.
I'm not sure if I'll fix it or leave it there... leaving it there could be fun.