Last episode Clone War Season 4 Epis 22 - Revenge
While Darth Maul (yes he is alive and back) was about to kill Obiwan, Ventress comes to kill Mauls Brother Savage Opress too. Here the follow conversation:
Ventress:It looks like I'm here to rescue you.
Obiwan: When did you become the good guy?
Ventress: Don't insult me.
Obiwan: Ah, what a lovely sight to wake up to.
Ventress: Don't flatter yourself, Kenobi.
Obiwan: You've never been much to look at, especially now.
Savage (Mauls Brother): The witch and the Jedi.
Darth Maul: Here for our taking.
Ventress pass one of her lightsabers to Obiwan at this point.
Ventress: I want that back.
Obiwan: That's fine. Red's not my color.
To see directly go to 17:00 minute