I think obviously he is in love with this woman and wants to have sex with her and he is trying to tell her how much he loves her. I think they decide in the second verse either to have sex or not to have sex, but she still doesn't want to.
Then, on the 'imperfect day', they have sex and it ruins what they have, and she will no longer be with him anymore.
This song reminds me of a situation I'm in.
I think obviously he is in love with this woman and wants to have sex with her and he is trying to tell her how much he loves her. I think they decide in the second verse either to have sex or not to have sex, but she still doesn't want to. Then, on the 'imperfect day', they have sex and it ruins what they have, and she will no longer be with him anymore.
It's a very beautiful and sad song.