Everyone in the military wears, or at least has their dog tags with them at all times. It's for identification reasons. They're also a sorce of comfort in some sense.
Most soldiers wear them around their neck, some keep them stuffed in one of their many pockets. But you always wear yours on your neck, and Graves loves it. He's dreamt so many times of pulling you in with your dog tags, like he's read about before.
Days pass and this feeling has yet to be sated. So, one day, the urge gets too strong and he just has to take this opportunity. Graves comes to sit down beside you in the common room. It's not uncommon for the leader to be a friendly person to his team, it helps with morale and keeps the team's community and commitment up.
But this time, he has different intentions than just chatting and having a laugh. He has something he wants to try.
He reaches out quickly, noticing you're lost in a daydream. He wraps his fingers around the tags itself and pulls. Watching as it jerks you out your dream, he continues to pull, wanting you close to him. What he wasn't accounting for, though, was that the chain would break. The fucking betrayal.
He freezes, watching the chain slink out over your shoulder, having snapped behind your neck, leaving your dog tags laying in his hand and the broken chain dangling down below. They aren't that expensive to replace but it'll still be a pain in the ass. Guess those little stories he read were wrong. He can't even meet your gaze, staring at the tags and the details on them.
"Well, shit," he says finally.