Ghost who is so touch starved he will allow any type of contact.
Everyone just assumes he hates it by how he presents himself, or more like, how people perceive him. Big, scary, deadly, animalistic. It was only common they would think staying as far away from him was what he wanted. When in reality it was what they wanted, because they feared him.
So when you, the young, nice archivist starts warming up to the team, Ghost can't help but want to be close to you. There's something about you that just screams tranquillity, something they lack in their lives. And since they are desperate to have it, when they find you touching them they simply allowed it.
They quickly found that you enjoyed textures.
Like when you slowly run your finger through Soap's mohawk, or through Price's wrinkles or Gaz's mustach, you just enjoyed the feel of especific things agains't your fingers. If not, then you would pull your hand away like whatever you were touching physically burned, sometimes it came with a squeak, but that was it.
Then ghost becomes desperate, days pass and you simply wont touch him, not even a tiny swipe with your finger against his gear or balaclava or whatever thing about him he knows you would enjoy the texture of.
He starts to think maybe you see him the same way everyone does, and he hates it, because theres nothing he can do about it. He's unable to change, not after roba.
Thats when he notices...you never approach him, but you're always staring at him, right in the eyes. So he absorbs the only thing you're willing to give like a sponge, staring at you without blinking even after you looked away.
So it's a surprise when one day you simply lean closer to him, and he holds his breath, going completly still as if the slightest movement would scare you off forever. Your hand raises slowly towards his face, only for the tip of your finger to touch his upper eyelashes.
Ghost couldn't be more delighted, so from that point he would always lean over you, his face close enough for your hands to reach, going as far as to bat his eyelashes as if hypnotizing you to do it. Wich always worked.