Spring 2004.
Your avatar has one performance where it shows up. Or at least in the performance with Natasha St-Pier, couple days earlier.
edit:
ah... sorry... I thought you were talking about the tongue piercing....
The lip piercing is from summer/fall 2005. Shows up in few press photos.
edit:
The lip piercing is visible for example in Jérémy's birthday party photos:
The tongue piercing is visible for example in this performance with Jenifer:
