reply guy
1. A man who behaves in an overly familiar way and is always replying to the social media messages of a woman he doesn't know or is barely acquainted with.

2. An annoying man who replies to social media messages, in general - whether this annoyance is due to a perceived know-it-all attitude, excessive familiarity, banal arguments that the annoyed user doesn't feel compelled to reply to again and again, or violation of some imagined pecking order.
Mental health improves 120% when reply guys are blocked or muted