Facetime connects to iPhone when Mac is started up

I made a Facetime call from my Macbook Air last night. Since then, when I open my Mac, I get a message on my iPhone 14 that says, "Connected to Macbook Air. You can disconnect to remove this iPhone from the Mac camera list." I didn't use my phone for any Facetime calls, so why has it suddenly started connecting to my Mac when I open the Mac, even when I'm not on a Facetime call? When I disconnect, it's only until the next time I open my Mac, then I get the same message on my iPhone. Help, please?