I sit and look right at you
You stare back into my eyes
But you have no idea
You're the reason that I cry
I think about you constantly
And wonder what it'd be like
For you to hold me in your arms
One sad and lonely night
To know that you are right there
To wipe away my tears
And right there to save me
From all my hidden fears
But you're already taken
You have someone elses heart
And I know that a relationship
With you will never start
So as you sit here staring
Back into my eyes
My outside smiles back at you
But inside my heart still cries

Cheyenne Ashley

http://www.poemhunter.com/poem/when-you-love-someone-who-loves-someone-else/