I pee myself every time

I'm very embarrassed to be writing this, but I'm in my mid-twenties and got a sex toy for the first time ever a couple of weeks ago. A vibrator. However, everytime I use it I pee myself. A lot. Doesn't matter that I just went to the bathroom or even if I don't drink anything hours before using it. It happens everytime and I'm so embarrassed. My husband says it's normal, but I feel gross. It never happens during sex. I don't know what to do. I went to my gynecologist recently and everything looks normal, so it doesn't seem to be any medical issues going on and I'm not taking any medication. Help!

Edit: It's definitely pee. It smells of urine and it is not when I orgasm because I never get that far because I get so turned off because I pee myself.