Remus Lupin was the Moon; everyone in Hogwarts knew that expression. So it was after a 'secret admirer' placed a note under Remus' door three months ago, which read:
Remus Lupin, you are my moon.
All of Hogwarts knew that Remus 'the moon' Lupin was the Casanova of Gryffindor tower. So it wasn't a surprise when he got a note slipped under his door that night, but it was perplexing that a week after Remus found that note, it fell out of his pocket in the hall. That was when the whole of Hogwarts realized it wasn't a secret admirer; it was Remus Lupin's Sun. Remus Lupin's Sun was the most prominent talk over dinner that night. Everyone pondered and prattled over who the enigma could be. Some said Marlene, others said Sirius, and a few even dared say, Lily. But Remus seemed wholly unbothered by the entire bit. Not even fazed, he just marched along throughout his years of youth. He continued to hang out with his supposed boyfriend, Sirius and didn't mind telling him that people speculated about their affair- which didn't exist, by the way. Sirius was a lone man waiting until after Hogwarts to start romantically exploring. After many excruciating months of waiting patiently, the chatter finally died. Without someone to latch onto, no clues, and not even a single person speaking up about it, everyone eventually just... stopped.
That was what happened around a year ago. No one spoke about the incident, and Remus always kept the note close to him. Because to everyone else, it was a confusing message from an unknown person. To Remus, it was a love confession to the highest beauty. Almost more beautiful than him. The writer of the note, the beautiful man who unknowingly graced Remus' presence whenever he made a stupid joke or thought up a prank so foolish and dull-witted that even the higher powers wouldn't be able to carry it out, Remus was secretly swooning.
He was even dumb enough to write it in his handwriting. No charm could have hidden it from Remus anyway. He knew it all too well, the notes asking to meet up after class (during class), copying notes off of Remus, which he thought he was doing secretly, but Remus just pretended he was too focused to realize, and the carving into that tree. It was all too familiar not to recognize. No one else in Hogwarts could remember that handwriting- Although everyone should have known, according to Remus. Finally, after many weeks of pondering, Remus realized how apparent his Sun was. The cheesy pick-up lines and dragging him to the 'most romantic spots in Hogwarts,' carving their initials into so many different things- anything he could stick a knife through, evidently. Books on his bedside table were titled 'how to be alluring' and, illegally, 'how to make a love potion.' He always reasoned they were for Lily, not him. If you need help guessing who his Sun was, let me tell you the initials he had always carved on surfaces.
J+R
The Sun and Moon.
Eventually, they found each other. Even if it took an entire eclipse, they did. James Potter, the Sun, and Remus Lupin, the Moon, found each other even if it wasn't intentional. Even if James just yearned to tell him but was too scared and decided on a note, even if Remus would never know. He could settle with him wondering. But, of course, the Sun doesn't expect to stand eye to eye with the Moon every eclipse, does it? Remus was happy knowing, but he wanted more. So that one night during Hogsmeade weekend, when the two friends disappeared from their large group,
The Moon kissed The Sun.