So there is a bit of controversy in whether the creation of the Earth was divinely led evolution or immediate creation by the hands of God. For more research on that I would highly suggest going to the https://www.kolbecenter.org/ and https://foundationsrestored.com/ I was originally of the opinion that it was divinely led evolution. Even to the point of arguing extensively with Protestants for it. However, I then looked into the Kolbe Center’s research and borrowed the foundations restored course from a friend. I have to say, I went in dubious of the proof for direct creation, but they knocked off my socks. They had very solid proofs convinced me pretty well that evolution at least was flawed and rather outdated. That context aside, here is an article that I found on some random creationist website. It offers a very good and cool understanding of why men have nipples. https://askjohnmackay.com/god-created-man-why-men-nipples-wasteful/ It basically says that since Eve was “bone of his bone and flesh of his flesh” (his = Adam), it was necessary that Adam contain all the parts that Eve has. Hence why Adam would have had an XY and Eve and XX. If Adam had had an XX then Eve wouldn’t be “bone of his bone, and flesh of his flesh” because the Y would have had to be placed in her by God. I am not sure how scientifically sound it is as I am not a geneticist, but it is and interesting question that I have taken way too seriously :) Regardless, I think part of the reason God gave men nipples was so that they wouldn’t feel left out :)

P.S. Sorry if I came across a little offensive on my first response.