iCloud Keychain verification problem
Hi, I have a iPhone 5s (iOS 8.4). The phone keeps asking me to verify my iPhone on Keychain. I tried to 'Approve with Security Code', then Apple sent 6-digit iCloud Keychain verification code to my girlfriend's iPhone (iOS 7), I have no idea why and how. I then entered the 6-digit code into my phone, and then my 4-digit iPhone passcode, but it did not work. How to resolve the issue.
The Keychain is showing 'Pending'.
thanks
iPhone 5s, iOS 8.4