Some people are persistent about love; they're quick to declare it and refuse to let it go. They continue to tell the person they love that they love them even after being rejected, sometimes more than once. They find their own pride in love, they hold their head up high because they're in love, and they never imagine that it could be a bad thing. Santana could never be one of those people.
She loved quietly until it was too much for her. She hid her feelings because she believed what she was taught, and she was taught that they were wrong. She had too much pride and too many tears. She would never admit her love, but when you think about it, it's a wonder nobody noticed. You could see it in her eyes, feel it in the way she touched Brittany, like nothing was wrong in the world as long as she was happy. You could tell in every long look, every watering eye, every word in Britt's defense or protection. Santana definitely never felt that way about anyone else, so every time she ran from her exposure down McKinley's hallways and to somewhere lonely where she could cry without being seen, it must have hurt. And every time the girl she loved was dancing with someone else, it must have hurt. Because first loves are forever, as Quinn Fabray famously said, and Brittany was her first love, but she wasn't Brittany's.
When Rory or Artie got in the way, even if Britt had tried to convince her that she was hers, Santana knew she would need someone else to carry her home.