We all know they have a low alcohol tolerance but how would each react if they had a hangover the next day?
Sorry for the late reply. As for your question, if it was just their low susceptibility to alcohol, but they all have a high pain threshold. Harlequin got stabbed in the back a few times, and after a few?hours? He's already as good as new and feels great. So let's imagine an almost unbelievable situation in which they fully experience all the symptoms of a hangover. Let's put a spell on them, so to speak…
One more thing: I don't write fan fiction like Destiny or Servitaur. I am not a professional, so I apologize for the possible dryness of the text. You can add to my words if you want, or maybe point out an inaccuracy.
Pierrot -
If you've always taken care of him before when he was injured or bullied, then obviously this innocent-looking boy is using his condition to get more attention from you. Of course, he will be more clingy than usual: he can rub his head against you if you allow it, or purr all sorts of "tenderness" under his breath. However, if you, on the contrary, feel disgusted by his touches and other romantic actions, he will overcome his pain and his desires, as he always did for you.
Harlequin -
The guy is not one of those who openly shows his pain to others, especially in front of you, his potential victim. If it hadn't been for the other circus performers, he wouldn't have gotten out of bed. But he can get the balls out of the bells - he knows how to do that, we've already done that. No matter how bad he feels, he's still an evil gremlin and won't miss a chance to piss off Pierrot. If things are bad for him, then Pierrot must be much worse.
Jester -
He controls everything, regardless of his condition. As a leader, he won't show his weakness even to those close to him. Of course, he will feel bad: the headache and nausea will not go away. Therefore, perhaps a little more Fools will suffer on stage that day than usual. But as I said, it won't affect him much, at least you won't notice it.
Ticket Taker -
This man will do his job regardless of his condition, because he does not want to let the Fool down. While he's in this state, I advise you not to annoy him. Of course, he will control himself, but you don't want to be left without a tongue, do you?)
Doctor -
It's a dubious situation, despite the fact that he has some kind of unstable split personality. In any case, this guy would have found a way to alleviate his symptoms, although I don't think it would have had much effect on him… Type… He has a cute little man tied up here who urgently needs to be dissected, I doubt a headache will stop him.