He Ain't Much, But He's Mine - S4-E5
Plot hole: Marcy gets her hair done like Pegs. Everyone makes fun of her saying she looks ridiculous. All she has to do is wash it! Its obviously held up with hairspray but Marcy acts like there's nothing she can do about it.
Answer: It's implied that Steve filed for divorce since in s04e16, "You Gotta Know When to Hold 'Em", Marcy says that Steve is suing for alimony. Alimony is something that has to be requested when filing for divorce. Although the show doesn't spend time on the actual legal proceedings of their divorce.
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