Souma is really susceptible to cracking up, and even memories will put him into laughing fits. But being self-conscious about this, he always tries to hide it. When he does this again at a clothing store his friend works at, the friend asks him why he does that, especially when it's so easy to tell anyway. Later, Shun also repeats the same sentiment...
I think you've got it all wrong.
لا أعتقد بأنّ هذا ما ظنَّه النّاس
Tu fais fausse route.
Não acho que foi isso.
Вряд ли всё было так.