I phone safety

Change your passcode and don’t share it.

Reset your FaceID; installing only your face.

Then see if this “2nd person” can still unlock your phone.

Don’t share your unlocked phone.

Do you often hand them your device when locked? Are they a family member? A child?

the odds of any random person in the public being able to unlock your device is very small, around 1 in a million.

why can my sister unlock my phone with fa… - Apple Community

About Face ID advanced technology - Apple Support