>>49916309
Characters can get both Affection and Trust Fall at the same time if they met the Loyalty requirements for both at the time (usually 20k Loyalty to be absolutely safe in Tensei-P). If you only go for the bare minimum shown in [Sexual Upgrades], they will only gain Trust Fall and never Affection Fall.

For characters with both Affection and Trust Fall, they will never touch you. The game treats this like as if sure, they have feelings for (You), but keep it behind the Friend Zone Wall, so to speak. If you were to Train someone who only has Trust Fall and no Affection Fall, after Training the game will tell you that they felt betrayed by what you've done and could no longer trust you (Trust Fall lost + character becomes uncooperative). If they have both Trust Fall and Affection Fall, the game will tell you after training that (You)r actions caused their feelings for (You) to overpower the Friend Zone Wall (Trust Fall lost but character now only has Affection Fall remaining and will act accordingly)