Remus steps off the train, worn overnight bag slung over one shoulder, and a soft cat carrier slung over the other. The cat inside the carrier meows unhappily, and Remus murmurs a few soothing words.
Waiting at the end of the platform, behind the gates, is Sirius. He appears to be wearing a hideous (beautiful, Remus' mind corrects) crop top in a horrid (amazing) colour, ridiculous sunglasses, and is also carrying a giant and very colourful bouquet of flowers.
He's also grinning really excitedly, waving the bouquet, and Remus can't help it: he smiles.
When he reaches Sirius about a billion years later (Remus had not had the heart to subtly charm the old lady in front of him out of his way) he lets the overnight bag slide to the floor as Sirius' arms come up to embrace him. The bouquet is half-assedly leaning against Remus' back, probably being squished in the process, and Sirius kisses him, and continues kissing him, even as the cat in the cat carrier meows (again, unhappily). Remus ignores the cat, his' left hand pressed against the small of Sirius' back to keep him close, their bodies aligning together perfectly, and he's home.
His heart swells and he thinks, this is it.
"Of course I'll marry you," Remus says when they break the kiss, picking up the thread of the conversation they were having before he left.
The smile that spreads on Sirius' face is everything, and then Sirius is kissing him again.
The cat in the bag meows. Sirius laughs and peers into the bag, grinning happily, and says a few nonsensical words to it. The cat doesn't sound impressed. He exchanges the bouquet for Remus' overnight bag, hefting it onto his shoulder with ease. He then takes Remus' hand and pulls him in for another quick kiss. "Rings first, or home first?" he asks.
Remus considers the tired cat, the semi-squished flowers, the smile on Sirius' face. "Rings first," he decides. The cat can wait. The flowers can wait. But Remus? Remus absolutely cannot wait.