The Bonfire of the Manatees
This is the 374th episde, it aired on 9/11/05
Spoiler warning
Homer agrees to let Fat Tony shoot a porno at his home in compensation for football gambling debts. He coyly sends the family for a July afternoon at Santa’s Village, but when they return ahead of schedule, Marge blows her top and storms out leaving Homer to watch the children. While camping at a rest stop, Marge befriends an attractive marine biologist who tells her that Homer will never appreciate her if she continues to run back to him. Homer and the rest of the family go in search of Marge and discover she has run away to save the manatees. The family is able to find Marge who shoots Homer down leading him to believe the only way he can win back his wife is by saving the manatees himself. While almost being killed by a gang of jet skiers and the mob (the porno tested poorly because Homer’s stomach growling ruined the audio), Homer proves to Marge that he’s not as self centered as she believed and the couple is reunited.