Looking for an old chastity story (F,m)

It’s a chastity story I read a very long time ago. A teenager knocks up his girlfriend and his mom pays for an abortion. Then locks the son in chastity until he turns 18. The weekend he’s supposed to be unlocked him and his mother get in a car accident and she dies and the son wakes up bound in the basement of the paramedic that found him and keeps him locked.