A classic douchebag move where one
party of a conversation drops the entirety of the discussion and leaves completely, most notably without a goodbye.
The most common example of this is
seen online where during a conversation someone will inevitably leave the
chat and log off without a
single warning or hesitation, and not out of frustration or shitty internet connection.
This also applies to real life when speaking to someone either in person or on the phone where they either turn their attention elsewhere or hang up, respectively.