Moe Letter Blues

Moe Letter Blues is the twenty-first episode of Season 21.

Plot
From Fox's publicity website: "As Mother's Day approaches, Moe narrates an episode in which he writes a letter to Homer, Apu and Reverend Lovejoy, who are vacationing with their children, and threatens to run away with one of their wives. While the trio tries to determine whose wife Moe is referring to, Homer, Lovejoy and Apu flashback to the intimate moments they initially ignored between Moe and Marge, Manjula and Helen Lovejoy. But when the boys return from their trip, they're in for the surprise of their lives."