Kirishima was just being his normal self until he sees Bakugou giving you a bunch of words and asking you if you know a song that has those words because he thinks there isn't a song that had this words

Bakugou:"the words are Easy-Bake, God, Odd, Grass, laughing, money, Bread, Pain Pills, and cool"

Bakugou smirks because he thinks a song like that doesn't exist and he thinks you can't sing since your normal really quiet