Comedy is all about the context. In the early chapters, the love potion was being usesd more or less unintentionally and the person responsible was arguably suffering the most while everything was so over the top and silly that you could easily suspend disbelief and judgment
The Nurse scene was played very real, with a student coming to her in a moment of weakness to voice a concern about themselves and the nurse seemingly taking advantage of that situation to have her way with her, which is a common real world problem
Not only that, but the difference of character is important too. Toudou starts off as completely unlikable, and only gives the potion to prez because she thinks it’ll make her sick and doesn’t want to test it herself. So when that blows up in her face in such an over the top way, we can at least laugh at the schadenfreude, as well as her insane goal-post-moving afterwards (“it’s a good thing I enjoyed that otherwise you’d be in huge trouble btw I’m definitely not gay quit asking”).
This chapter opened strong with the “handsome Prince” character realizing that she actually likes girls: something you don’t always see in yuri series (usually it focuses on specific relationships rather than sexuality as a whole). And so far Tsubasa has felt like one of the more down to earth/sympathetic characters. I thought it might have been a wholesome chapter about gaining an adult confidant who she can discuss her sexuality with, but then she just gets molested by a teacher. There’s no comedy, it’s just messed up.