More dialogue we never got to see:
[In the elevator on the moon of Endor]
[Cue Muzak version of the Cantina theme in background]
Vader: "Hey so I hear you're a Jedi Knight now..."
Luke (looking down): "Yep..."
Vader: "Hey that's great your mother'll be so proud... "
Luke (scowling at Vader): ...
Vader (rubbing his arm): "Oh right... right... whoopsie..." (laughs nervously)
Vader (filling the silence): "Sooo how about those Ewok things--pretty cute huh? Just want to hug them... sooo cute..." (Vader realizes what he's saying and coughs)
Luke (rolling his eyes): "Mmmmhmmm"
Vader (looking up): "How long does this elevator take?!"
Luke (under his breath): "Someone'll get choked for this I bet."
Vader: "Hmmm? You say something Son?"
Luke: "Don't... just don't call me that, ok?"
Vader (feelings hurt): "Sorry... I just--"
Luke (ranting): "Can you imagine what I'm going through? I lose my uncle, find out you're my father, lose master Yoda, the Rebel Alliance is pulling for me to do the impossible, I'd have better luck trying to tickle a Wookie! "
Vader (high pitched): "Use your Anger?"
Luke (shouting): "Just shut up!"
Vader (looking down, kicking the carpeting with the toe of his boot): ...
Luke (looking away) ...
Vader (timidly): "We could always take in a podrace some time... just the two of us..."
Luke (reluctantly giving in to something that sounds kind of fun): "Sure... yeah... maybe sometime..."
[Elevator doors slide open with a 'WOOSH']
[Luke and Vader see two Imperial Stormtroopers guarding a doorway in the hall]
Vader (awkwardly pretending to have been speaking all along): "Uhhhhh... The Emperor will not sit Idly by while your puny band of insolent Rebels attempt to meddle with the plans of Galactic Empire! You -will- be bent to his will--to the will of the DARK SIDE!"
Luke (feigning bewilderment)...
[Luke and Vader pass the troopers and head into another hallway alone]
Vader: "They totally bought it!"