Find my Iphone

The other day my friend and I started sharing our locations with each other. I could see his and he could see mine. I opened the app this morning though and noticed that he was following me on find my iphone but I couldn't see his location anymore. Curious to see if he went out of his way to unfollow me.

I went to imessages to see if there was that little grey text that says "xyz stopped sharing their location with you" but I didn't see anything...

Thoughts?