how could an angel break my heart :'(

http://www.youtube.com/watch?v=AA59qj5v-GI&feature=related

I heard he sang a lullaby
I heard he sang it from his heart
When I found out thought I would die
Because that lullaby was mine

I heard he sealed it with a kiss
He gently kissed her cherry lips
I found that so hard to believe
Because his kiss belonged to me

How could an angel break my heart
Why didn't he catch my falling star
I wished I didn't wish so hard
Maybe I wished our love apart
How could an angel break my heart

I heard her face was white as rain
Soft as a rose that blooms in may
He keeps her picture in a frame
And when he sleeps he calls her name

I wonder if she makes him smile
The way he used to smile at me
I hope she doesn't make him laugh
Because his laugh belongs to me