Felt like I had to pee during sex

My boyfriend and I were having sex and it felt so good but I felt like I was going to pee all over him. I didn’t pee beforehand which made me think it was actually pee, but this sensation was so strong it didn’t feel like just pee. Like if I were standing, (we were in missionary), I wouldn’t be able to hold myself up, and my knees would’ve buckled, it was that strong. Eventually I had to stop him because it was too much.