Uh, Harry wasn't with them when they went to the Chamber of Secrets, and as bbraeven pointed out below, it was the Room of Requirement, not the entrance to the Chamber when this scene took place (in the book)
It's a brilliant picture but I just want to point out that in the book they finally kissed outside the Room of Requirements not the Chamber of Secrets........ Brilliant picture though!!
I ABSOLUTELY LOVE THIS MOMENT
Anyways, GREAT ART! I LOVE IT TO BITS
Well done, you