Trusted devices

You can remove a trusted device but you will no longer be able to use that device to access iCloud or other Apple services until you sign in again on that device, at which point it will again be a trusted device. See the information in the "View and manage your trusted devices" section of Two-factor authentication for Apple ID - Apple Support including the following:

You can also remove a trusted device by selecting Remove from Account from the device list. Removing a trusted device will ensure that it can no longer display verification codes and that access to iCloud, and other Apple services on the device, is blocked until you sign in again with two-factor authentication. If you need to find or erase your device before you remove it from your trusted device list, you can use Find My iPhone. 

My choice would be to change my passcode and not divulge it to anyone. See: Use a passcode with your iPhone, iPad, or iPod touch - Apple Support

Hello ~ Take a look here:

Two-factor authentication for Apple ID*

*View and manage your trusted devices

You can view and manage a list of your trusted devices on iOS, macOS, and in the Devices section of your Apple ID account page.

~Katana-San~