Talking in my sleep

It seems that I talk in my sleep, a lot. I’ve seen video recordings that my girlfriend has made on her phone of it (since I didn’t believe her), and it is pretty funny. I’m told I do this all night, every night, without fail. I will have full blown conversations with whatever or whoever I happen to be dreaming about. Sometimes I moan and groan and make loud noises between conversations. I never ever remember doing this or even what I was dreaming about.

As you can imagine this is driving my girlfriend nuts since she can’t sleep while I’m having these conversations and making these noises.

Does anybody know of anyway to stop doing this so I don’t keep her up all night?