Sirius
When asked, Sirius Black would assert that James Potter and Remus Lupin are friends. One of each-other’s best friends (he holds the actual best friend slot for himself of course).
Sirius knows what it is to love and be loved by both of them. He knows that they hold a kind of love for each-other. But he would also say himself, Sirius doesn’t really understand their love. The love he has for each of them is so different.
You see, Sirius loves Remus in the all-consuming way. The one that leaves him constantly feeling that he cannot have enough of Remus. The one that makes him crave Remus' kisses more than cigarettes. That makes him feel sort of itchy when he is not around Remus, like Remus is the balm for his soul. He probably is. Sirius really and truly loves Remus in every way.
Sirius loves James in the most natural way. As easy as taking a breath. He loves James as the other half of his soul. Through James, he has learnt to love himself as well. James is his warmth, half of his heart walking outside of his body, the very air in his lungs. The kind of love that feels soothed when James is in the room with him. The kind of love where he would do pretty much anything to see a smile on James' face. Sirius loves the other half of himself that is James.
He has loved both of them since he met them.
And given that James was the one that invited quiet Remus to join what would eventually become the Marauders, Sirius has always assumed that they liked each-other. They must, right? They spend all their time together. Well, all of their time with the Marauders and therefore with each-other.
But in all the ways Sirius sees love, he does not see them between James and Remus. He has never heard loud expressions of love like Sirius enjoys expressing for James. Okay yes, Remus and James do sometimes seem to sit close together and talk quietly in the common room or at parties. But it's always quiet. Always just between the two of them. Always seeming like a normal conversation from the outside.
He does not see the constant need for physical affection that he has with Remus. Okay yes, James does sling his arm around Remus whenever they walk together, or hold his hand when they're lounging around the common room. But James is a very tactile person, he does that with everyone.
They have a different relationship to what Sirius does with each of them. Unsurprising given that Sirius feels romantic love for one and platonic for the other. On some level, Sirius does know that they love each-other in their own way.
And there are times over the years that he sees it. Feels the warmth and comfort of it. They are some of the memories and actions he comes to cherish most from two of his favourite people.
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One of the times Sirius noticed James’ love for Remus, is during full moons.
Ever since they found out about Remus’ condition, James had apparently taken it upon himself to ensure that Moony misses nothing of class when he is recovering. Sirius didn’t know until about their 4th year when he found Remus studying from the almost illegible notes from Prongs.
He supposed he had always assumed that Moony got notes from Lily or something like that. It had made sense. Lily may not have explicitly been told of Remus' condition. But she was smart enough to figure it out and as Remus' most common study buddy, it did not seem like a leap to think that she wrote notes for him.
But not. Once Sirius noticed, it was all he saw. During the week of the full moon, even before Remus needed to stay resting in the dorms or the hospital wing, James seemed to pay extra attention in class. He did not engage with Sirius' banter as much. He kept to his meticulous, and impossible to understand for Sirius, notes.
Sirius truly could not understand it. Why it was James, and how Remus could even get anything helpful from the notes. So after he found out, Sirius asked.
Moony had only shot him a surprisingly serious look and replied; “I've never had to ask him to do it Pads. He just does. He even makes little notes in the margins of extra information I might find interesting. He knows exactly what I need, and writes these notes better than all of the rest of you. Lily included. I can read it no problems. Leave of it."
Sirius took the hint and never asked again.
More obvious than the notes, was during on particularly bad full moon.
It was a year or so after they had become Animagus and had fallen into habits. Unspoken rules were accepted. Things like Moony liked them close to him and liked the company for as long as possible, but he wanted to make his own way back to the hospital wing or the dorms. He needed to feel like he had some control over the night still and all of the other Marauders respected it.
But this full moon, Remus was covered in his own blood by the time he managed to transform back.
This full night had come after Sirius had realised that he was totally and completely in love with his Moony. This made full moons harder. One of the worst things he had experienced was seeing Remus in pain. Even small levels of pain. It was unusual for it to be this bad.
So, Sirius couldn’t cope. He couldn’t move. He could only curl up into a ball in the corner and watch the love of his life writhe in pain, knowing there was nothing he could do to fix it. Nothing to help him. He couldn’t even comfort his Moony. Not when all he could do was stay in this ball trying desperately to not feel like he was back in his parents’ home.
Peter was busy comforting Sirius so he hadn’t noticed immediately when James helped Remus up. He only noticed when Moony was slung across Prongs’ shoulders in that muggle firemen way.
“Let’s go.” Was all James said.
James carried Remus all the way back to the castle like that. Never stopping or slowing down. He seemed to keep up a quiet commentary that only Remus would have been able to hear.
Often when he was in pain, Remus hated to be touched. Any kind of pain. Remus wanted his space. Sirius had learned to accept it and know the appropriate moments to step away. Especially after full moons. In the same way he took pride in walking himself back to the castle, space was a way for Remus to hold control of something when he was vulnerable.
And yet on that day, Remus remained pliant in James arms. James must have done some sort of pain numbing spell because Moony did not seem to be in pain. He was actively bleeding all over James’ shirt though.
Remus did not attempt to argue or insist he be let down. Beyond that he was actually clutching onto James. His own hand was wrapped around one of the arms that supported him.
James delivered Remus to the hospital wing and remained by his side. Remus continued to clutch James hand for the remainder of that day. Sirius could only watch from the chair opposite, surprised at this obvious affection.
Every full moon from that night on, James was the only one allowed to physically help Remus get back to the castle. Remus seemed to lean into him. And James took the weight without hesitation.
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Remus’ love for James is most visible to Sirius during James’ active days. The days where Prongs cannot seem to sleep, cannot seem to stop moving, cannot seem to stop talking, but also cannot seem to stay focused on one thing.
It was not an everyday occurrence. It seemed to happen once every few months or so.
And Sirius, who loved James dearly, oh so loved his sleep. He could last a few hours watching Prongs pace and listening to him prattle. But he could not last longer than Prongs could.
It was during these times, that Moony seemed take over without hesitation. He would disappear for hours at a time with Prongs. Years later Sirius discovered that at all hours of the day they would be out at the quidditch pitch. James would practice his quidditch and Remus would sit reading his book in the stands. James was able to keep moving and active, even able to keep up a constant rambling conversation with Remus, and Remus seemed to never tire of it.
When he found out this fact, Sirius realised that at some point, James had gone first to Remus during his active days. Moony seemed best equipped, and Prongs noticed.
Remus would stay with him during the night. He seemed to be the only one that could convince James to eat during these times. Small things that James could eat while moving.
And when Prongs inevitably crashed, he seemed to somehow always crash in Remus’ arms on the common room couch. Sirius had watched it in amazement more than once. One minute James would be pacing and talking to Remus, and the next he was sprawled out with his head in Remus' lap. Remus hardly seemed to notice. Only continuing to read his book and using a free hand to stroke James' hair. Sometimes when James had been going for more than a day or so, Remus would be asleep a moment after James.
James leaned into Remus when he was having these harder days. Looked to him for company, and literally collapsed on him when his energy ran out. And Remus accepted it without question.
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After they left school, Sirius noticed these things more. Noticed the way that James loved Remus, and the way Remus loved James. Noticed that this love was as important as the love he had for either of them. Noticed the gaps they filled for each-other.
Sirius came to appreciate the quiet, need filing love that Moony and Prongs shared. And he could not be more happy that they had each-other. That they were both always loved in the quiet.