&gt; Except before Facebook, we wouldn&#x27;t have known this unless we went out of our way to find out, or just ran into our ex in the street.<p>Or had any common acquaintances. Or read newspapers (publishing engagement notices in them used to be a thing).<p>For most of human history, if someone you used to be involved with was engaged to be married, it wasn&#x27;t particularly unlikely that you&#x27;d hear about it, and in many cases be either socially expected to participate in celebration related to it or be pointedly excluded from them.