I have a question around how iMessage works. If I use my Apple ID to login to someone else’s phone, download an app on their device and then log out. Will my iMessages stay synced with that device? While I am logged in will they be able to see my iMessages? Will they only see messages I send while I am logged in or will they see my past messages as well? Once I log out will they still be able to see my messages new and past?