How to distinguish satire from black humor?

This is an example of the combination of humor and irony. Humor can be telling jokes to make people laugh, or saying something that is inconvenient to say directly. The use of humor is vivid and natural, and it also expresses its meaning, such as a famous example:

Roosevelt's friend asked him one day if the American army had a military base there. Then Roosevelt asked him in a low voice, can you promise not to tell the second person? The friend nodded, and Roosevelt smiled and said to him, Me too.

Roosevelt's use of humor not only rejected his friends, but also made him humorous, so the connotation of humor is very rich, definitely not just the appearance of making people laugh on the surface, and the landlord does not have to distinguish it clearly. Satire doesn't have to be humorous, and humor doesn't have to be irony. Many things can be expressed. Why is it so clear? Such things often happen in life. You want to tell a joke to ease the atmosphere. As a result, others think you are satirizing him, which is humorous to you and ironic to him, so the landlord doesn't have to distinguish it so seriously. If it is serious, you will lose.

Black humor can also be regarded as a cold joke. For example, he often says something that he thinks is funny, but in fact, no one thinks it is funny. Therefore, what he said can also be regarded as black humor.