Red-String Theory
You don't always feel it, wrapped around your pinky like an invisible force, sometimes tugging or falling loose. The latter is the worse feeling, always wondering if your soul mate is just farther from you, or if something terrible has happened. Never fully reassured until the tug comes back. Sometimes Jim thinks he can almost see it, like a passing glimmer, a thing strand that somehow traverses whatever distance is between him and the one person he's destined to love with his whole heart, and will do the same right back.
In his younger years it was the only thought that kept him going. Knowing one day someone was going to love him without him needing to ask. They were chosen, born to love him. He keeps it like a mantra, like a prayer in the deepest parts of his heart when being a drunk and a delinquent feels like a rut he'll never get out of.
Leonard McCoy didn't feel his string for the first few years. Became almost convinced that he must not have a soul mate until just before his tenth birthday he felt it. A tug so strong it shook his hand. He looked around, curious, but nothing else happened. From time to time he'd feel another tug, or a slack in the line. It was so strong sometimes he could swear his soul mate was close.
But he didn't find him right away, and to hide the shake in his hand he took up drinking, and pretended it didn't matter. Thankfully it wasn't his dominant hand and didn't interfere with any work he had to do. That would have been too much to try and figure out. When was he supposed to meet this person?
Jim recognizes it before Bones does. Bones blames it on being terrified of going into space. When Jim misreads it as Bones not wanting to know his soul mate, he does his best to hide it. He hooks his thumbs in his pockets when he walks, keeping hands poised at his side to look relaxed even though they sometimes dig into the pants. If he gets too close to him, he puts his hands all the way in his pockets, feigns a look of boredom, and finds the nearest exit before he gives in to the urge to kiss him.
Having a soul mate wasn't supposed to be like this.
Eventually Bones notices the weird dance Jim seems to be doing when they get too close, too comfortable. How evasive he is physically. It confuses him at first. Jim's not the type to acknowledge physical boundaries. He'd rather slide right passed them with a smirk and a nod. So what makes him so different?
When he brings it up, Jim almost doesn't say anything. But at the same time he's exceptionally tired of trying to not bring it up. Does Bones really not know? In a huff of frustration he pulls his hands out of his pocket and grabs Leonard's. The reaction is almost immediate. Warmth. Hope. Need. Home. It stuns the older male for a moment.
"Why were you trying to hide it?" he finally asks.
"I thought you didn't want me." Jim admits.
"You idiot." Bones pulls him into his arms.
He's always wanted Jim. He just didn't think he deserved him. But someone else did. And who is he to argue?