へそで茶を沸かす

へそでちゃをわかすhesodechaowakasu

expression · godan verb

1. what a joke!
2. don't make me laugh!
3. to split one's sides laughing
4. to be convulsed with laughter
5. to boil tea with one's navel (using the heat generated by laughing)

Study it in Yanamino