Is there a way to make "find my iPhone" not work?
Remove an iOS device or Mac by turning off Find My iPhone

Remove a device from Find My iPhone by turning off Find My iPhone on the device.

On an iOS device: Go to Settings > iCloud, then tap to turn off Find My [device].

Note:   You can also remove your device by turning off iCloud completely on that device. Turning off iCloud turns off all iCloud features on the device.

You can read Apple's full article for more details, iCloud: Remove your device from Find My iPhone