How to stop someone from tracking iPhone's location using Find My?

My dad is able to track my location through the Find My iPhone app although I don't have him as a shared person. The only thing I can go off of to try to figure this out is one picture he had sent to my mom showing my exact location at the time using the Find My iPhone app showing my iPhone or my Mac book and one of his shared items. I think he's using the devices affiliated with my cloud but I'm still unsure how he was able to do that and how I could reverse it.

I'm still very confused about how he can do this, does anyone know how I can stop this?

[Edited by Moderator]