Watch The Sweetest Heart for Free: How to Stream the Movie Online at 123Movies. . High school sweethearts Maddie and Nate reconnect when Nate returns to their hometown to lecture at the hospital. Still hurt from their breakup, Maddie tries to avoid him. However, they eventually form a friendship, and Nate helps her as she secures funding to expand her cupcake shop. Just as Maddie and Nate rekindle their romance, Nate learns that a career opportunity awaits him in Boston. Devastated, Maddie returns the promise ring he gave her long ago and prepares for the grand reopening of her shop. Nate soon realizes how much he left behind, and must decide if his future lies in Boston with work or in his hometown with Maddie.