I'm not sure about triggers going way back to prior chapters. But if you look at Chapter 9 of the attached walkthrough, there are clear immediate triggers, which I try to outline below -
https://f95zone.to/masked/mega.nz/3...KrlaffCLh.G0A3WYoXXVTht2LZkDIisl7tfNYi69jTGpg
1) "I bet your idea of variety in the bedroom is deciding whether to take your socks off or not! *smiles* Boring!"
MC's Reply - "I could tell you something...\"***This option has the possibility of leading to a sex scene
2) "(Should I tell her of other relatives I'm attracted to?)
MC's Reply - ""Yes" ***This option has the possibility of leading to a sex scene
"But, I am also attracted to other family members..." ***Choosing 3 or more from this section can lead to a sex scene
"Talk about your mum" "Talk about your aunt" "Talk about your twin cousins" "Talk about Milly"
3) "You may have spoilt the plans I had for this evening, but feeling the size of the thing I'm currently gripping, it could still turn out being a most enjoyable night! *smiles* So? ..."
MC's Reply - "It would be rude to stop..." ***Sex scene"