Convo-butter
One who compulsively interrupts or butts in to other people's conversatons without being invited.
Ugh! Bob is such a convo-butter! He's always interrupting our private conversations.
Hey I don't mean to be a convo-butter but what you said to Bob is compleatly wrong.
Hey I don't mean to be a convo-butter but what you said to Bob is compleatly wrong.