From @Kuro_96_neko

"Len-kun, in 96neko's song, 'Len Kun Now!', how embarrassed were you when you realized she hid a banana in your hair?"

Well, I can't speak for Len, because I'm not him, but I imagine that would be embarrassing because clearly Len's Banana Sensor didn't go off quick enough for him to notice sooner...such a shame.