Episode 31 of "Malcolm in the Middle"
s02e15 The Grandparents

Lois's nightmare parents, Victor and Ida, come for a surprise visit and throw the family into turmoil not only with their mere presence, but by promising to pay for a much-needed refrigerator and then reneging after Lois and Hal spend money they don't have. Lois and Hal are forced to ask Ida and Victor to stay longer to help take care of the kids while they work some crazy overtime. Victor treats Reese like a king while Ida tortures Malcolm for being a smart wimp. Victor gives Reese a live grenade, and when Reese inevitably arms it, Malcolm's quick thinking blows up the new refrigerator instead of the whole house. Hal extorts money out of Lois's parents to pay for the damage. Francis motivates his fellow cadets to break out for a weekend and go to New Orleans for Mardi Gras, but then spend the entire time there suffering from eating bad sushi.