When a male is masturbating and another moves up unbeknownst to the masturbator and then strikes the testicles at such a time that the masturbator is just beginning to ejaculate.
The side-effects may include vomitting, depression, and penis explosion, which can in turn lead to death.
I have always wanted to pop a collar because everyone always masturbates at my house for some reason and I'm getting sick of it.
Yesterday i walked in on Theo masturbating and I popped his collar. Good thing he was already at the toilet because he threw up all over the place.