Cherchez La Femme

 is a perk in Fallout: New Vegas.

This perk gives female characters increased damage on other female targets, and unlocks unique dialogue options for members of the same sex.

Additional dialogue options
This perk can be used to convince the Omerta receptionist in Gomorrah to talk about the Family during the fourth part of the quest The House Always Wins.

You can flirt with Corporal Betsy in Camp McCarran.

You can use sleep with the prostitute Joanna in Gomorrah.

You can ask Sweetie to give her the key to Saint James' room for free.

You can respond to Rose of Sharon Cassidy's comment about not liking "soft men" by saying that they're rarely a problem for you. Cass will respond by nervously saying that when she's drunk, she doesn't care who she shares a bed with.

This can also lead to some interesting conversation with Benny when you meet him in the Vegas Strip.

Behind the scenes
"Cherchez La Femme" is a French idiom which translates literally as "search the woman" and can be understood best as meaning when a man has a problem, there is surely a woman at the source.