PCs naturally tend to do most of their talking with fellow PCs. But there are many cases in which it makes sense to call in an NPC.

Particularly if you're plotting behind your fellow party members' backs.

Transcript

Obi-Wan: I sneak past the troopers and get to a fighter.
GM: <roll> Okay, no problem.
[SFX]: Whooosh! {ship takes off}
Obi-Wan: Now what the heck's going on? I need to contact someone I can trust. I call Anakin.
Obi-Wan: No, wait. R2-D2.
Obi-Wan: Actually, no, Padmé.
Obi-Wan: On second thought, I call Senator Organa.
Bail Organa: Master Kenobi, glad you're still kicking. The Man's making his move.
Obi-Wan: Oh? Something I should know about?
Bail Organa: It's all going down at the Jedi Temple.
Bail Organa: {narrating flashback} "Clones bumping off Jedi. Saw it with my own peepers."
Bail Organa: {narrating} "A bunch of them tried to get me. Some poor Jedi kid ate a plasma-bolt with my name on it."
[SFX]: Pow! Pow! Pow!
Bail Organa: {narrating} "I had to vamoose lickety-split."
Obi-Wan: That sounds... serious. Where are you now?
Bail Organa: On my ship, leaving Coruscant.
Obi-Wan: I'll meet you on board.
Bail Organa: Right on. We'll stick it to the Man.
Yoda: Who's "the Man"?
R2-D2: The Man is a nebulous paranoid concept from the 1960s regarding governmental authority. So, what with you being a budding politician, in a sense, how can I put it...
Padmé: You da Man!