Hanger-on noun
Someone who hangs around with a famous, rich or important person or group of people in order to get personal advantage from them.
Despite being a magnet for hangers-on and overzealous admirers, John's still a poised and polite young man.
Mary's such a hanger-on. When I was poor, she avoided me, but now I'm rich, she is always following me.
Used to refer to a person who flatters people who are powerful
This noun dates from 1540s.
To do domething based on your emotions rather than for rational reasons
I can't believe that Tom beat his classmate. He's always the one who let his heart rule his head.