Generally a day can't go by without my students saying something wonderfully funny, but when I'm teaching I try to keep the giggles to a minimum for fear of losing the students' attention. Today I broke my rule quite spectacularly when one of the ichinensei class jokers was asked to translate days of the week. My JTE held up various cards with the days of the week on them, and for some reason, this one student had me unable to control my laughter with the following:
[Monday card held up]
Student: "Kayoubi!" (Tuesday)
I'm certain this student was actually struggling with the words, but on "Fishday" I felt my shoulders dancing and the floodgates opened and I couldn't control the mirth. Upon seeing my amusement the class went into hysterics. One of them even shouted "ganbatte, sensei!" - presumably "do your best, sensei, to control yourself". Sorry to my JTE for that!