Just a boy

I feel like the boy who sits in the corner till called.
The silent, ever serving butler.
The one who is at your beck and call.
And fades away the moment his duties are done.
I'm the second son.
Place priority on the first.
I'm the boy who's there when you call.
Gone when not needed.
And that's what I am. A boy. A son when needed. Otherwise, just a boy.