Frank Sinatra be careful its my heart

Be careful, it's my heart,
It's not my watch you're holding,
it's my heart.
It's not the note
that I sent you that you quickly burned,
It's not a book
I lent you that you never returned.
Remember,
it's my heart.
The heart with which so
willingly I part It's yours to take,
to keep or break,
But please, before you start,
Be careful,
it's my heart.