[Jess walks out of the bathroom]
LUKE: You’ve been in there for two hours.
JESS: Yeah, well my hair just ain’t bouncin’ and behavin’ today.
“Bouncin’ & Behavin'” was the slogan for Pert shampoo advertisements in the early 1980s. It might seem hard to believe that Jess is referencing an advertisement from before he was born, but the phrase was so popular that it is still widely used when discussing hair care and products in general, even today.
The Annotated Gilmore Girls 