The phone, and the paper trail you did not know you had

A short practical list, because most people have never thought about it.

Your phone probably shares your location with somebody, and the setting is not always where you expect. Your browser keeps a history, and so do your keyboard suggestions. Cloud accounts sync messages and photographs onto other devices, including his. Shared bank statements show which shops and which town. A car may have its own tracking.

You do not need to change any of this today, and changing all of it at once is itself visible, which is a thing worth knowing. Somebody who does this work will help you think about which changes are safe to make and in what order. Until then, use a device that is not yours for anything you would not want read.