Leggy Siren is a term first used in Season 1, Episode 1 of "Grounded for life." it's used to describe a women who's attractive, with spectacular legs who lead men on. Sean uses the term to describe Claudia when lily revealed boys who age view her mom as being more attractive.
"this isn't about me being a bad dad, this is about you being a leggy siren, who's describved our daughters self esteem let's go with hit.