Chains and Pools (Morgan X Reid!Male!Reader)

You fiddled with the 2 feet of chunky chain you carried everywhere. You ran your fingertips down the length of it, the cool, smooth texture calming you. You let out a quiet sigh. Chain had always been a relaxing thing for you. You let your self start humming, and rock back and forth. Spencer had told you to wait for him at the office, and since everyone was in a meeting, you took a seat as his desk. You laid the chain down on the table, and ran your pointer finger along the links. He had promised that he would take you to the olympic sized pool a few miles from the apartment you shared, as you always liked the water. The pressure, and the silence was always very calming, much like chains. You heard a door open, so you turned around, hoping it was Spencer. It wasn't, so you watched him with great interest. You had memorized whose desk was where, so the minute he went to one, you'd know his name.
"hey kid! Who are you? Why are you at Reid's desk?" he called. He was big, and fairly intimidating. You went to speak, but found your mouth unable to form the words to answer, so you just say there, rocking back and forth a little faster.
"You shouldn't be here. You know that?" He kept getting closer, and you could see Spencer's head in a room, but you didn't want to interrupt the conversation.
"Can you speak? Why are you here?" You kept moving your head from him to Spencer's head, seeing he was getting ready to leave. He put his hands down on the desk, and lowered his head to try to look you in the eye. You moved your head to avoid it.
"Why aren't you answering me? Why are you here?" You let your hands start to flap, seeing everyone in the room start to leave. The door opened and Spencer saw you and his eyes lit up.
"(Y/N)! You found me!" You smiled and got up, completely ignoring the man who was looking at your brother with great confusion.
"Reid, who's he? He was sitting at your desk and he wouldn't tell me why."
"He's my brother. I told him to come wait for me, but the meeting ran late, so I'm assuming he just sat at my desk to wait, right?" You nodded your head, moving your feet, and your hands still moving.
"Why isn't he talking?" He raised an eyebrow. You looked down, upset to have made him mad. Spencer looked at you.
"Bad verbal day?" you nodded, happy that he could explain. "Here. I found this and I thought it would be better than the one that's rusting you have" he rustled through his bag and pulled out a chain. You took it gently, and started playing with it, visibly calming down.
"Care to explain anything Reid?"
"He's autistic. He gets really non verbal someday. Basically, he couldn't answer you. He wanted to, but couldn't. It probably didn't help that you look big and scary to him"
"Me? Scary?"
"Kid, am I scary to you?"
"(Y/N), that's Derek Morgan, I work with him. He's a nice guy. He won't hurt you." Spencer whispered. You flapped your hands a little faster, and made a humming noise before nodding. You could hear him scoff, making you feel bad. You kept your eyes at your feet before you heard heels clicking on the floor and looked up.
"(Y/N)! Hi! How are you!" You had met her a while ago.
"Baby girl, you know him?" Derek asked Garcia.
"Yeah. He used to wait with me when he came from school to see Reid because of all the computers. He's really good at code and HTML, actually. I made him an access card because he was here so often. Just made everything easier" she said. You offered your hand to her, and she put her hand on your wrist, letting you grip hers; it was you guys version of a hug. "Did big bad Derek scare you?" She teased. You smiled slightly and laughed.
"Come on (Y/N). Let's go swimming" Spencer said with excitement. You let go of Garcia's wrist and went back to Reid's desk to throw your bag over your shoulder. You stood there, contemplating what to say to Derek. You were about to open your mouth when Spencer was by your side, and you decided to say something next time you were here. Derek looked from you and Spencer to Garcia with great confusion before she just laughed.
"He gets used to you. I promise. Just don't be surprised if the first thing he says is something about psychology or the quantum theory. He's like boy genius, but quieter. But once he starts talking, everything comes out at once." She smiled before shuffling back to her computers, leaving Derek to think about if he was actually scary.