What got left in the car

Choices:
A. Lunch
B. Mum
C. not enough information
D. The kindle
The kindle
NOT A PROBLEM:
Person A: I was really surprised to learn that your mum used to live in Wales.
Person B: My mum? No, she never did that. You must be thinking of someone else.
Person A: No, I’m not. I told her how my parents are from Cardiff and she said she’d lived in Newport until she was 18.
Person B: She did not.
Person A: Yes, she did.
Person B: Nope. She’d have told me.
Person A: Well, where do you think she grew up, then?
Person B: In Yorkshire, of course. Like the rest of us.
Person A: You’re wrong, you know.
Person B: Bet I’m not.
Person A: OK, well, I’m going to phone her and ask her. You’ll see.
PROBLEM:
Person C: You still have my Kindle.
Person D: I do not. I gave it back to you two weeks ago.
Person C: No, you didn’t. You said you were going to, but you never actually gave it to me.
Person D: I did. I remember. It was when we were having lunch in Starbucks.
Person C: No, that’s when you said you’d left it in your car and would get it when we’d finished eating but then you forgot all about it.
Person D: Look, I gave it back to you. I think you’re just trying to get a new Kindle out of me, and let me tell you: it ain’t gonna work.
Person C: You’re just trying to keep my Kindle for yourself. Well, I’m not going to let you get away with it. I’m going to tell your mum, so there.
It really depends whether the parents are in a position to shed any light on the contentious issue or if involving them would just make an awkward situation worse.
If parental input will be helpful, welcome the chance to confer with them; if it won’t, let the other person do what they will and trust your parents to have more sense than to get involved in a purely private argument.