When Berta goes on vacation, she finds a friend, Consuela, to temporarily replace her.  However, when Charlie sees how nice she is (huevos rancheros in the morning, mint on the pillow, swan towels, etc), he wants to keep her when Berta returns..  Rather than firing Berta, he makes Consuela his nighttime maid until he's caught.  Berta makes him choose.  He chooses her.  It's always been her.

Meanwhile, Lyndsey breaks up with her ex-husband and begins dating Alan again.  Alan begins to correctly think that her ex, Chris (Judd Nelson) is stalking him.  At the end of the episode, Charlie lets Chris in the house and points him to Alan's bedroom.  But it's 2.5 Men.  He'll be fine.