I thought this one might be a pretty tough code to mutilate, but I was wrong:

Original English Text:
I love you.

Translated to French:
Je t'aime.

Translated back to English:
I love you.

Translated to German:
Ich liebe dich.

Translated back to English:
I love you.

Translated to Italian:
Ti amo.

Translated back to English:
I love to you.

Translated to Portuguese:
Eu amo-lhe.

Translated back to English:
I love to it.

Translated to Spanish:
Amo a el.

Translated back to English:
Master to him.