Without getting into the deeper meaning of the song, which Gaga herself has explained, I've read a few comments from journalists and so on refer to the chorus as basically nonsense, albeit in a non-derogatory way. But this isn't entirely true; "amor" is a reference to the Italian word for love, "morta" is Italian/Latin for dead ("mort" is Latin for death), as in the subsequent line, "In her tongue she said, 'death or love tonight'". In other words the first 3 lines of the chorus are the "lady in red"'s peculiar language for saying this dichotomy.
Without getting into the deeper meaning of the song, which Gaga herself has explained, I've read a few comments from journalists and so on refer to the chorus as basically nonsense, albeit in a non-derogatory way. But this isn't entirely true; "amor" is a reference to the Italian word for love, "morta" is Italian/Latin for dead ("mort" is Latin for death), as in the subsequent line, "In her tongue she said, 'death or love tonight'". In other words the first 3 lines of the chorus are the "lady in red"'s peculiar language for saying this dichotomy.
[Edit: Correction/clarification]