Fingering

Hi girls! So I have a question,

I haven't had sex yet, but I do other things w my boyfriend. Anyway, whenever he goes down on me and also starts fingering me, I feel this need to pee that is so uncomfortable and totally turns me off. It's so annoying because it gets to the point where it's so uncomfortable that I have to ask him to stop, I go to the bathroom afterwards and I don't even actually pee, but I'm left with that sensation. Because of this reason I still haven’t been able to finish while he gives me oral sex and it’s starting to get really frustrating. Does anyone know why that happens and what I can do to make it stop?

Thanks!:)