What are they doing? What is the 'story' of this gif? :)

Translation will be in the comments since it's a gif. I've no idea what the game is, but I'm assuming it's some sort of card game, so:

PANEL 1

S: "Natsuki, if you play that one, you're really going to lose, you know."

N: "Huh—!?"

N: "Is this really your first time playing a PSP?"

S: "Yup, that's right."

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PANEL 3

N: "I won!"