Santana didn't want Rachel to know it, but she absolutely loved when Rachel forced her to sing songs off of musicals with her. Whether it was a duet for Glee clubs, a musical movie marathon complete with hairbrush microphones in Rachel's bedroom, or god forbid, a typical Friday night sing-along by the piano with her fathers, Santana would always snark and complain and drag her feet about it, but ultimately, she would, seemingly with the greatest reluctance, participate. What she didn't tell Rachel was that she loved the way Rachel's eyes would shine with such unabashed pleasure, how her entire face seemed to glow with happiness; she didn't tell her that when she sang the roles that Rachel had chosen for her, she could really feel through the music and find in her own voice all the emotions of the part she had been given, and release out some of her own tightly guarded feelings along with it. She didn't tell her that sometimes she had to try to keep her guard up from bursting into joyful laughter or from crying genuine tears, that when she danced it was never planned, but rather spontaneous response to the music they were making. And she never could stop herself, no matter how hard she tried, from breaking out into a huge, unguarded grin by the end of every even slightly upbeat song, knowing full well that no matter what she didn't say, Rachel could undoubtedly read it all very plainly in the wake of her smiles.