Be Careful It's My Heart

Sweetheart of mine, I've 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, it's my heart.