Diff'rent Strokes - Season 2 Episode 11 : Thanksgiving Crossover (1) 1986

The Alders and the Drummonds are together again in New York, and Arnold, Willis and Kimberly plan a second Thanksgiving feast with friends Diane and Ruthie. But even the huge Drummond penthouse isn't big enough to hold the exploding tempers that threaten Phil and Larry's long-standing relationship, on a special one-hour episode featuring the stars of ""Hello, Larry."" Morgan and all the kids get caught up in the feud when Larry learns friendship doesn't necessarily make for good business.