@ Kaelathor
There's no bug in your savefile. What's happening is the following:
- your students are at max corruption (level 6)
- but your lifeguard is only at mid corruption (level 3)
Contrary to what the text says, the real problem is that your girls are *too corrupted* for a scene to show: if the girls were level 4 you'd see the second warm-up scene, but it is no longer possible to see this scene in this save.
Instead, what you can do is to raise the lifeguard to level 5 (that's two potions), and that will allow you to see the third warm-up scene.
As a general rule, in this game you can miss scenes when you corrupt some girls much faster than others. In this case you corrupted the schoolgirls faster than the lifeguard, which is unusual, since the lifeguard is much easier to corrupt.