a and b conversation
Butt out means you're not welcome in the conversation. It’s like when your mom interrupts your text with her own nonsense.
My dad said, 'Butt out, I’m trying to talk to my friend.'
She kept interrupting me, so I told her to butt out and then she yelled at me.
I was trying to explain my day, but my brother said, 'Butt out, I’m more important.'