[Lelouch was just waiting for some teenage girl to literally run into him right (again)? That's not what happens here. It almost happens as Ai comes barreling out of game alley at speeds most humans would not be capable of keeping up with watching. At the last millisecond she spins around Lelouch with a grace most people don't possess even in their little pinkies and stops just on the other side of him.
She fixes him with a look of slight confusion as if he's the one who appeared out of nowhere or as if she's sizing him up for something else entirely.
Then Ai grabs his wrist with a decieving amount of strength for someone of her stature and starts to drag him into the game alley.]
What are you standing around for? Let's play a game.