A great little animation. I'm not going to say I've heard the song before, but after hearing it now I'm definitely going to check it out.
I love the twist in the song, going from this cute little romantic tune to a song about a mental man that'll literally kill to stay with a girl.
Your graphics weren't the best, but I felt they fit fairly well with the track, considering how simple the song itself is. The animations could do with some work, seems like they're mostly tweens so they look fairly unnatural.