6th Year, potions lesson, amortentia, Pansy Parkinson
This is an idea that's been rattling around my head for awhile, but I don't really have the writing skills to properly expand upon it.
In the movie, there's the scene where amortentia is revealed, and there's the bit where all the girls move in towards it, then compose themselves and back away once Slughorn closes it. One detail that always stuck out to me was that Pansy Parkinson looks particularly embarrassed, glancing around a bit before regaining her composure.
What if it's because she has a secret crush? I'm a bit of a sucker for Harry/Pansy when it's done well, so could go that angle with it. (Don't care for Draco/Hermione tho, and it's hard to find the former without the latter.) Could be it's someone else entirely whether it be serious and angsty or cracky and silly.