For men: witnessing childbirth negatively effecting your sexual arousal to your child's mother?

I’ve heard that when a guy watches his wife/so give birth that there’s a significant chance that he looses sexual interest in her. I’m not sure if this is a myth, or what’s behind it. I can see how in theory the guy sees this part of the female anatomy that’s supposed to be exciting, get turned into a gory mess with your kid hanging out of it might change things, but I have no idea—never been there. I’m curious if any guys can relate to this question and to hear their thoughts/experiences.