The question of Sam's sexuality occupied Kurt all week. At least until he saw his performance with Quinn and agreed with Santana's judgment.
It wasn't even that Kurt was falling in love. It was the hope of having someone with whom to cultivate a rapport. Sam didn't recoil from Kurt's attention. Instead, he reeled and blushed in a way that both endeared and gratified: he charmed.
Even when Kurt pressed the nature of Sam's affection, Sam remained a man of honor. And when Kurt reneged on their partnership and realized he'd disappointed Sam, that itself was a novelty to treasure.