What is the most probable relationship between the two speakers?

M: Hey, wow!? Where did you get all of this stuff?
W: I bought it. So, what do you think of my new entertainment centre? And the widescreen TV...
M: Bought it? But where did you get the dough to buy all this? Have you been using Dad’s credit card again?
W: No, silly. It’s mine. It’s a student credit card.
M: A student credit card? Why did you get one in the first place?
W: Listen. Times are changing, and having a credit card helps you build a credit rating, con- trol spending, and even buy things that you can’t pay with cash.., like the plane ticket I got recently.
M: What plane ticket?
W: Oh yeah, my roommate and I are going to Hawaii over the school break, and of course, I needed some new clothes for that so...
M: I don’t want to hear it. How does having a student credit card control spending? It sounds like you’ve spent yourself into a hole. Anyway, student credit cards just lead to impulse spending.., as I can see here. And the interest rates of student credit cards are usually sky-high, and if you miss a payment, the rates, well, just jump! Let’s sit down and talk about how you’re going to pay things back. That’s the least I can do.