I'm sorry , I had to decline your request since this is an Adult group, hence ,we only accept users of 18+ years, and since in your profile says you are 15, we can't let you join.
I did not see that specified anywhere on your page, specifically in your rules. I might make note, though, not much in your group is rated 18+, which is [normally] a sign that anyone "mature" can join. My mistake.