Internal Affairs is episode 23 of family guy season 10. It was originally aired on May 20, 2012.
Peter encourages Joe to have a one-night stand with his attractive new partner in order to even the score with Bonnie for her own indiscretions. But when Bonnie finds out and threatens divorce, Lois insists that Peter get them back together. Meanwhile, Peter has another run-in with the angry chicken which makes for yet another epic fight.