How do I delete suggested/recent contacts in mail in ios9 on an iPad?

An iPad my kids use is synced to my iCloud account, but not email. When we set up my sons email and he starts to type in a name it pulls up everyone I've emailed from my iPad or phone giving him access to all of my work and personal contacts, which I do not want. How do I fix this? I have tried tapping on the information for the contact but delete from recents is not an option.