When I was 15 - 17 I was reading a lot of fanfiction on Wattpad. Back then "I dated them as a prank / dare but then I fell in love with them and when they found out all hell broke lose" was a big thing. Like, the amount of Frerard stories I've read with that premise is insane, (considering it had nothing to do with their personalities.)
You can think it's an awful trope all you want, but considering that's THE most stupid rich teenage boy thing EVER, I don't understand why it's not a staple in the Marauders fandom?! You want canonically awful public school wankers as Marauders? This is your trope!
The potential alone of Sirius daring to date a Slytherin, and James trying to get it on with Regulus to get back at him for this awful idea? Everyone is hurt? Everyone is angry with everyone? The drama???! The self-reflection and growth afterwards?
It works for every single Marauder x Slytherin, Marauder x Marauder, Marauder x Gryffindor girls, Marauder x OC ship
We all love Operation Walburga's Arbitrary No Kissing Ever Rule - think that, but intentionally.