I don't know about men butts, but in my experience with women's prep isn't always necessary nor is long dilation. Even for women with little experience in that area.

You of course should do both, but it can be a spontaneous thing without it going horribly wrong most of the time. Even only using her own natural lubrication if you are getting that engine running good.

But, men and women are not the same, so the same metrics and actions cannot just be moved over from one to the other even with their butts.