Consiglio: Dealing with a serial interruptor? Give them space to talk, but IGNORE what they say, and when you can… simply pick right back up where they interrupted you as if they never had.

Learned this years ago and it absolutely works. When the SI (serial interruptor!) does their thing, go ahead and let them. But now you have two goals:

1. Don't lose your train of thought! Keep in mind where you were when you got interrupted.
2. Ignore every single thing they say, no matter how incendiary, rude, stupid or whatever.

Once they've run out of steam pick right back up where you left off. If you really want to add some shade, resume what you were saying with, “As I was saying before you interrupted me…” but that's optional.

NOTE: Don't confuse an SI with the normal give-and-take of a regular conversation with friends. I'm talking about someone who's learned that by interrupting they can keep you off balance and control the flow of the conversation. Use the shit out of this method on THOSE idiots. Think of it like conversational judo.

Edited to add: When you get interrupted and respond to what they say during the interruption, you are simply training them to do it again. Don't feed the monster!

Edit II: Electric Boogaloo – People in comments are calling this out as passive aggressive. YES, DEFINITELY. But there are plenty of reasons why maybe you can't be completely up in the SI's face, so just consider this another tool in your toolbelt. 🙂