In “Close Encounters,” a ninth-season “Dallas” episode, Sue Ellen (Linda Gray) is at the Ewing Rodeo when she approaches Mandy (Deborah Shelton), who turns away.
SUE ELLEN: Mandy. [Mandy turns back to face Sue Ellen.] I’m Sue Ellen Ewing.
MANDY: I know.
SUE ELLEN: May we talk?
SUE ELLEN: [Steps closer] I have something to tell you that might be helpful. You’re not the first girlfriend J.R. has had. [They begin walking together.]
MANDY: That’s helpful?
SUE ELLEN: I’ve seen the way he’s treated all the others.
MANDY: Look, this time it’s different.
They stop walking, face each other.
SUE ELLEN: Is it?
MANDY: Yes, it is. J.R. and I love each other. You just don’t know him the way I do.
They resume walking.
SUE ELLEN: Mandy, I know J.R. every which way there is to know him. And he’s never going to change. Never. He’s going to use you like he’s use all the others, and then he’s going to walk out on you and never come back.
MANDY: You really want me out of his life, don’t you?
SUE ELLEN: Not for the reasons you think. I don’t want him back. Mandy, I’m telling you this for your own good — because J.R. destroys every woman he goes to bed with. It’s by the grace of God that he didn’t destroy me. Don’t let him do it to you.
MANDY: [Begins to cry] Thanks for the advice. You’ll forgive me if I don’t take it because you don’t know what the hell you’re talking about.
She begins to walk away, when Sue Ellen grabs her.
SUE ELLEN: Isn’t it strange how the mistress always thinks she’s smarter than the wife? If she’s so smart, why is she the mistress?