I think this song is about a very short romance with someone you don't really have a crush on, but after it happened you feel very guilty and you try to explain to yourself and that person why it happened. It's always a struggle to do such and this song is about that struggle. Luckily the lightness of the tune itselfs reveals that short romantic flings aren't really something you should worry about and should enjoy anyway.
I think this song is about a very short romance with someone you don't really have a crush on, but after it happened you feel very guilty and you try to explain to yourself and that person why it happened. It's always a struggle to do such and this song is about that struggle. Luckily the lightness of the tune itselfs reveals that short romantic flings aren't really something you should worry about and should enjoy anyway.