Dads friend
The guy who acts like he's your dad's best friend but is really just there to flirt with your sister and make your life a living hell.
"Dad's friend? More like the guy who tried to kiss my sister in front of everyone at the family reunion."
"He's not a friend. He's a menace who stares at my sister like she's a snack."
"I swear, that guy followed my sister home from school once. I had to beat him up."