Try this
- Name the recurring joke and ask that it stop in the relevant setting.
- If someone argues about intent, return to the concrete request rather than trying to prove the joke was objectively unfunny.
A worked example
“Please don’t make my slow replies a joke when we’re with friends.”
An invented example to adapt, not a real exchange or a script you have to follow.
Before you leave it here
Ask for the specific behavior to stop without being drawn into whether everyone else found it funny.