Happy Tears

One-shot. HG/HP. Hermione cries almost incessantly after Ron leaves her and Harry while they're on the run and hunting Horcruxes, but why is she crying, exactly? How do her tears turn to happy tears? Inspired by the lyrics, "You'll only cry those happy tears, and though I'll make mistakes, I'll never break your heart," from the song "I Swear" by John Michael Montgomery.