To tell a joke and let it hang. Dry humor. The more dry, the better. The faith of the jokester to drop a joke and not even crack a smile.
The joke will do its work, and he’s confident of that. No need to laugh and “show” everyone that it is supposed to be funny.
Laughing at your jokes is cringy–unless you have a hilarious laugh, then the joke just gets extended.
Dry humor requires confidence. To tell any joke with confidence and not laugh at it will instantly 10x the funny factor.