he could just feel comfy with you, i mean come on, your profile is based off of bubbles from powerpuff girls, you seem pretty comforting to me. he might not be social but he still could find comfort and/or safety when being by you. thats what i would think anyways. try and get closer with him (if youre comfortable with that) and try and see if it helps you understand the situation any better! i hope this helps haha
