Answer: R2-D2 and C-3PO

Known on-screen as the friendly and inseparable duo, the actors who portrayed R2-D2 and C-3PO shared none of the affection of their on-screen personalities. During a 2009 interview with Metro magazine, Kenny Baker, the actor inside the R2-D2 suit, had this to say about Anthony Daniels, the actor inside the C-3PO suit:

I thought it was just me he didn’t get on with but recently I’ve found out he doesn’t get on with anyone. He’s been such an awkward person over the years. If he just calmed down and socialized with everyone, we could make a fortune touring around making personal appearances. I’ve asked him four times now but, the last time, he looked down his nose at me like I was a piece of s**t. He said: ‘I don’t do many of these conventions – go away little man.’ He really degraded me and made me feel small – for want of a better expression. He’s rude to everyone though, including the fans.

Lest you think the feeling of scorn was one-sided and Mr. Baker simply misunderstood Daniels’ feeling on the matter, we’ll let Daniels’ words clear things up. In a 2011 interview with The Mirror he explained:

I never saw him. I mean, R2-D2 doesn’t even speak. He might as well be a bucket.

Whatever the history between the two might entail beyond their public comments, we’ll completely understand if you’d prefer to Jedi mind trick yourself into forgetting this trivia tidbit and continue loving the adorable on-screen duo as they were presented in the films.