This chapter is not actually part of the story.
Whenever the author posts something about Tamen De Gushi they mark it with a #SQ, but for this strip, there weren't any hashtags, only the words 希望你的人生,自由而精彩。
So I think this is just a one-time thing.
If this bit is even semi-canon, it helps explain Sun Jing's intense reaction to the teacher blaming Qiu Tong for the pervert because Qiu wore a short skirt.
Other than, you know, that being a really dumb argument. But personal relation to such an argument would've amplified the disgust.