Contacts from other phones showing up in messages?

Hi, not sure if anyone else is having this problem. In my family we have 2 iPhones, they both have the same Apple ID for purchases and everything else. When it comes to iCloud they both share my iCloud for Find my iPhone and my dad has his iCloud set up on his iPhone to sync contacts between it and his iPad. Anyway, back to the problem, when I go to the compose message button and begin to type in a name, contacts from my dad's phone show up and vice versa, I have never noticed this in previous iOS versions and would like to know if there is a solution or if anyone else has encountered this problem.

Any help would be much appreciated...