Polite, softly spoken insistence can work wonders.

Just hold the big stick in a not-quite-inconspicuous way.

Transcript

R2-D2: Look, we need to contact Senator Binks. Trillions of squishy humanoid lives depend on it. This is save-the-Galaxy stuff.
Obi-Wan: We should discuss this somewhere safer.
Adam: Yeah, I don't like all this open sky.
Obi-Wan: The Sand People respect my territory. Follow me.
Adam: Whoa! With respect old man, I need to get home. With the droids.
Obi-Wan: I have no dispute with your mission. Follow me.
Adam: You have no dispute with my mission?
Obi-Wan: This way.
{beat}
Adam: This way?
Obi-Wan: Are you echoing me?
Adam: Echoing you?
Obi-Wan: Yes.
Adam: No.