CAN SOMEONE TELL ME HIS STORY?(WAS HE REALLY WITH THE X-MEN)? AND WHY DID HE LEAVE THEM?

He has a long history. You can find it all at:

link

well i'm not i big fan of gambit all i know is that
he was with the weapon x program like wolverine
than yes he joined the x men he is rouges boyfriend & i don't know why he left the x men