It was in original song which Kurts bird dies, so Kurt sings 'Blackbird' as a mourning song. In which Blaine realises his feelings for Kurt. A few scenes later they kiss
Original Song and First Time. Their first 吻乐队（Kiss） was in Original Song (this is when they got together), and they kissed again (and both 迷失 their virginities to each other) in First Time.
