Moonwater

After a particular prank where it was outed that Remus was a werewolf him and the rest of the marauders had a falling out but it also later on resulted in him and the youngest Black brother beginning to get close

Remus and Regulus are in the Room of Requirements studying, well more or so Remus studying while Regulus is messing with his hands and tracing his scars then connecting them like constellations