Younger model syndrome 

When a woman ages and another younger version of herself steps onto the scene, be it innocent or not, she feels threatened. Said women will unleash fury on her partner if he so much as looks at younger model with the slightest hint of admiration. This fury may not be overt but layered into nuances.

Steve:
Dude what's wrong with your girlfriend? She's got some serious sand in her vagina. She only seems to get like that when Alison* is around.

Mark:
Yeah she's just suffering from "younger model syndrome"


* The younger model

Younger model syndrome by Grouchokirst December 18, 2008