> Ideally you pair the shirt with a personality that never leaves any doubt that it is a joke.
Ideally, but that still doesn't really solve the problem. It's not really practical to counter an indiscriminate broadcast of contempt with point to point interactions. People who don't know you or don't know you well will always see your shirt, if you wear it out.
You want to do the opposite: indiscriminately broadcast a kind personality, then deploy the sarcasm in point to point contexts "that never [leave] any doubt that it is a joke".
I think this is pretty unreasonable, though. Are you against the husband/wife “I’m with stupid/I’m stupid” shirts? Generally it’s pretty obvious this is meant as a joke and not that one spouse genuinely degrades the other in public.
