Why does my iPhone automatically connect to my Mac Bluetooth?

Recently I noticed that my computer at work had somehow connected to the Bluetooth on my iPhone without me pairing them. When I select “forget this device” the Mac is deleted from the list of devices connected to my phone but then after I’ve been to work I will check again and see that the Mac has once again been paired with my phone and is in the devices list. Is this a hack?

I never paired my iPhone to my Mac at work and I don’t know why the Bluetooth on my phone would need to pair with a computer since I don’t play anything from my phone on through the Macs speaker. Can someone tell me why this is happening also how to stop it from happening? I usually leave my Bluetooth on my phone on because it’s connected to my Fitbit and my wireless earbuds so I would like to keep the Bluetooth on if possible, also the keyboard on the Mac is currently connected through Bluetooth so I can’t turn it off from the computers side either but I don’t want them to keep force pairing with each other. Is there a way I can stop this from constantly happening?