Why do I need to know faire la meuf/le mec?

Because it's a common expression that doesn't really make sense unless you know what it means.

What does it mean?

Meuf is verlan for femme. Verlan, as you might know, is French argot constructed by reversing the order of syllables in a word.

Mec means ‘guy’. This slang expression is used to say that someone is showing off, or flaunting themselves.

You may often hear it as (ne) fais pas ta meuf – stop behaving like a woman – but “woman” here is more than just “female human”, it implies boasting or acting cocky.

There's not really a great English equivalent, but when you hear this in a French context, you will know what it means.

It is usually used with le/la but it may also be used with the possessive ton/ta – faire ta meuf or faire ton mec.

Use it like this

Fais pas ta meuf – Stop showing off

Il fait trop le mec – He’s such a show-off

Fais pas le mec avec moi ! – Don’t get cocky with me!

Elle fait trop la meuf cool alors que pas du tout ! – She's pretending to be cool but she's not at all!

Synonyms

Se la péter – to show off

Se vanter – to brag

Se prendre pour un ouf – Thinking you are amazing