Masterbation causes me to pee, discharge or menstruate heavily?

My boyfriend likes me to wear my pantyhose without a skirt and I wear my panties underneath during our time together.

My boyfriend would rub my vagina so hard, and fast that I end up peeing, discharging or menstruating heavily. I couldn’t hold it in any much longer. My panties, pad and pantyhose would be wet and stained as a result.

I would always go to the bathroom first and it still happens.

Has this happened to any other woman.