Twin sisters

You're meeting your girlfriend for a date, you've only been dating her for about a week, so there isn't much you know about her yet. Arriving at the park, you see that she's already there and you smile as you walk up, greeting her. About time you got here, handsome. She gets up and quickly walks over, a lot more aggressively than you're used to. Before she can wrap her arms around you, you look up and see her again, walking around from behind a tree and you're shocked. There's two of her?! Except this second one looks shocked at first and then angry. Jewel! Leave him alone! You said you just wanted to test him. The girl next to you now has her arm around you, turning to face the other. Oh, calm down, Crystal. If he can't tell us apart, that's on him.