I wanna pitch something to you. I normally tell devs to ignore the idiots pitching them ideas, but I think this is actually a good one.
On Saturday afternoons, when Amy is at the lake, for a horniness of 3 she can tease the Headmaster.
It only seems logical that the Headmaster should be able to be like, "Uh-uh, you ain't tricking me again, lose the top right now," at a horniness level somewhat higher than that.
Since there are two girls standing there, the potential to increase horniness also exists as they gossip about how Amy is gonna fuck the Headmaster given enough time.
Just an idea.