The above phrase meant that a male was either becoming flirtatious, or causing a female to become very attracted to them.
An 'Unnecessary Man' is a male who can be associated with this era by looking dashing or wearing an appropriate costume, causing women to be attracted to them. It is usually applied to characters in books or films, and the look is often twinned with a bad or aggressive attitude.
"I saw Harry Potter again. That Snape is definately an Unnecessary Man."