It happened to me last year and it was my fault. With his knot (GSD) planted deep in me, I masturbated. After a great orgasm, the knot started to feel not so comfortable, so I decided to get it out. We have done that before, without any pain, three or four times. This time it was different, I don't what happened, but the knot was super stuck. like it was lodged between bones, or the knot grew bigger than ever, I don't really know. As I kept trying to expel it, the situation went from uncomfortable to painful in no time, and my boy got restless too... In the end, he yanked it out. It was horrible, it hurt for a couple of days... Now I'm a little scared to try it again, but I will for sure!