Unknown email address added to my Apple ID
Today I was restoring my iPhone from iCloud, after logging into my Apple ID from the device and agreeing to the Terms of Service, I was prompted to type the password of an email account (not my apple ID) used to purchase stuff from Apple Store, iTunes, etc... This second email isn't mine and when checking the purchase history of my Apple ID, there was nothing suspicious (that may be because I don't use a credit card, I prefere iTunes cards, phew!).
I changed my password and deauthorized every device able to download my purchases, and right now nothing looks out of place. All of this has me very confused because I was cannot explain how a second email could be associated to my Apple ID and why on earth would my device ask me for that password. I'm trying to figure out how to eliminate that email however I cannot seem to find it again.
Can someone help?
I'm using an iPhone 5c, iOS 8.2 if it helps.
iPhone 5c, iOS 8.2