Lời bài hát: Frank Sinatra. Ring-A-Ding Ding. Be Careful, It's 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 burn
It's not a book I lent you that you never return

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