Glamour, Lisa's Special Day.
I think you talk about a different game here, not this one. To my knowledge, BIBOAS doesn't have that scene. I did see it once, but it was a long time ago. Could be one of the fan mods for the original. Then again the dev put in every stupid idea his fans had, it might have been the base game as well. While it opens up a chance for more blackmailing (yay, more blackmailing), it would be inconsistent with so many aspects of the game, would be way beyond credibility - and yes, I consider getting drunk from one liquoir candy being more believable.