danm this is too hard for a blowjob scene hahaha, one time i killed the cockroach and the other she saw it without the peeping part and ran away screaming
It's not so much difficult as too long chains of events, and if you don't see the very first one, the rest won't happen.
For most toilet scenes, you need to see a cockroach once for the rest to even start playing out (except for the "new" food "spoiled" by mushrooms, the worst variation of food is poisonous mushrooms and hot peppers at the same time).
Moreover, there are as many as 3 "gradations" of the sister's encounter with cockroaches, and each one, starting with the second, has "differences" whether the brother was spying on her going to the toilet or not (there are also different dialogues depending on the number of purple hearts).
For 3 cockroach kills without vulgarity, you need to peek.
But for the primary vulgar scene, you don't need to find a cockroach after coming home, the main thing is to have seen it before and for the sister to be scared by it at least once.
In theory, then the sister will generally go to the toilet with some chance, which is not configured or not implemented at all in the current version of the game. There will also be some variations in the sister's random trips to the toilet, and under a bunch of conditions at least 3 different scenes will play out...