Le Portrait de Petit Cossette- insanity for beauty

Marcello was a painter who absolutely adored Cossette's beauty and wanted to catch it as perfect as possible. He didn't wanted it to disseaperar.  

Why do you want to paint me so much?

That's a silly question Cosette? You are so beautiful. You are probably more beautiful now than you will ever be again.

He just didn't want her beauty to decay. 

He didn't want to see it rotting away on his very eyes.

No I don't accept his behavior.

I just understand such madness

Her white arms do not exist in the real world, yet they also mark the edge of the world. They serve as bait to lure emotion. It is not a matter of her being an agent of love or an agent of death.

When standing in the presence of her sweetness, all else loses meaning...

all else ceases to exist..

.  

It was an insane love. 

Was he even loving her?

But is it bad to fall in love with something that is not human?
Is it wrong.. to have feeling for an illusion?

Scans and quotes taken from here.