What classy flowers? Justin vaguely remembers seeing a bouquet flying away when he saw that both of them were driving up. Oh, do you mean these two single flowers. Well it's only polite that he give both girls a flower.
Justin almost immediately recognizes that a game is afoot. He goes over his options in his head. The question is, does he play? He's completely at a disadvantage, so how can he cheat his way out or to the top of this?
Two words: Plausible deniability.
They don't know he's the sort for head games. Simply refusing to play and acting like there's no game puts him at an advantage next time, from being underestimated. It also makes him seem vaguely simple and innocent, which is endearing.
"Ladies," he says, offering each of them a flower, "You're both looking lovely tonight." He then looks back and forth between them, a confused look on his face like, "Oh wait, they're twins!" just occurred to him. "Umm. Which one of you... is Alyca?" He asks. Let's see how well playing dumb works.