Be Careful, It's My Heart

Sweetheart of mine
I sent you a valentine
Sweetheart of mine
It's more than a valentine
Be careful it's my heart

It's not my watch you're holding
It's my heart
It's not the note I sent you
That you quickly burned
It's not the 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, be careful
Be careful it's my heart