iMessage read receipts enabled without permission for one contact

I think it started after I shared my location with one contact. I sent the location and shortly after I could tell when they read the message. I thought they had turned it on for whatever reason. A few weeks later they told me that my read receipt was on. I checked the settings and it was off. Other people reported not seeing my read receipts. When I went to the persons contact info the red receipt was on. I told the person theirs was on and the same exact thing happened with them. At zero point did I ever go turn that on. Why would it just turn on like that?

[Re-Titled by Moderator]

Original Title: I turned on read receipts for myself and one contact without either of us knowing