machine gun mouth
A machine gun mouth is someone who talks so fast and so much it's like they're trying to make your head explode with all their words.
My brother talked about his video game for an hour straight. I wanted to punch him in the face.
My friend started telling me about his hair like it was the most exciting thing in the world. I felt like I was going to lose my mind.
My mom talked about her day for 30 minutes. I was ready to run away.