I almost decided to address micropenises here as well, but ultimately felt like that is a whole separate issue, and likely needed to be discussed a little more gently. I also haven't had that conversation with very many of my friends, so I can't say that I can make a generalization about how women feel about it.

Micropenis is usually caused by fetal testosterone deficiency or can even be caused by a botched circumcision, which I addressed in this article: https://medium.com/long-after-the-thrill/circumcision-widespread-legal-genital-mutilation-05f1c2e6740c

I have not personally dated someone with a micropenis, but it wouldn't bother me. I figure it's not much different than a finger ;)