Taylor swift is singing about the relationship her and her boyfriend have and how they share the pleasures of being together as it starts of, "man i didnt kiss her and i should have" and at the end it is, man I didn't kiss him as I should have. " and then she says,"before I said amen, asking god if he could play it again", meaning she wanted to relive that part of their relationship. The lyrics are beautiful. It highlights the beauty of spending time with the someone you love and share a connection to.