The joke was too low.

After others finish the joke-psychological suggestion method: keep telling yourself "nothing funny, just a cold joke." ☆☆☆☆ (highly recommended) Smile masking method: put your hand on your face and slide it down a little (to make others feel that you can't speak) ☆☆ (recommended) Compulsory tolerance method: hold your hand on the inner thigh (your own) and don't laugh. ★ (It is best not to use it)