Stop Right There
The way to stop bad behavior is to confront it on the spot. Any delay, any passivity, simply enables the behavior and emboldens the individual. This is especially true with passive/aggressive behavior, condescension, and disrespect.
There is some discomfort in confrontation, but there is long-term pain in enabling someone to continually irritate you and cause you stress. How do you confront?
Why would you say something so hurtful? What is your motivation for doing that?
If you continue to talk to me in that manner, this conversation is over.
That’s also how you can confront bullies. Poor behavior is propelled by a lack of resistance to it. This has nothing to do with rank, or hierarchy, or power, or experience.
It has everything to do with respect.