@cozmicfurry-UwU mm, I have a few
1. Toby and you are childhood friends (because lydra introduced you to him , because he's anti-social and you seemed nice!)
2. Maybe the reader is older than Toby by 1-2 years and is caring and protective , therefore Toby calling you his "Mother"
Or
3. This one is kinda cliché but ' reader having Tourettes and is innocent but has a bad school life or family OR MAYBE BOTH!!
Those are a few I could think about on the spot , if you need help I can help!! <3