The phrase "heart smile" is not a commonly used term, but it could refer to an expression of happiness or joy that is conveyed through the eyes, rather than a physical smile with the mouth. Full definition
and younger chicks jus all about drama these days I jus want a quite night of cuddles and relaxing... I'm 5» 11» blue eyes brownish blonde hair thicker build and have 2 amazing lil girls and a lil boy with smile that will melt your heart (sugarmommaclub.com)
Being with him and my husband make my heart smile.... (purebarre.com)