Limpet Whore

A name given to a girl who is your boyfriends 'best friend' who seems to be constantly attached to them 24/7 making it increasingly difficult to get any time alone together.

OR

Always seems to attach herself to ANY guy you end up liking.

Friend 1: "Hey girl, who you liking at the moment?"

Friend 2: "I Like Charlie, but THAT girl is always around him..."

Friend 1: "Uhhhh... what a Limpet Whore!"