I just found papers for a gps tracker in my bf’s pants?

So I was moving my bf’s work pants from today (we live together) and felt something in the pocket. I grabbed the stuff and it was a folded up manual for a gps tracker, and some plastic card with a troubleshooting number to call for the tracker. I looked it up and it’s a small round magnetic device thats made to be stuck to a car or boat?? Did he stick this on my car? I’m a bit freaked out. Should I keep quiet and check under my car or bring it up right away?