>>2887227If I have to guess, he probably referred to 性教育特別実習 (
https://www.pixiv.net/en/artworks/115819643) where the girl happily agreed to be a naked model for sex education class in hope to appeal to the boy she's in love with, but ended up forced to have sex with other guys and found out the boy she was aiming for already have a girlfriend. It's pretty sad ending but guglielmo always alternate between happy and sad story so it's not really a surprise.
As for a new, incoming work in C104:
彼氏の水着に着替えたら 真夏の海で男水着チャレンジ
https://www.pixiv.net/en/artworks/121206501 