Did the dad never change any diapers?
Micropenis is almost always evident from birth. Always afaik, but I'm leaving room for edge cases I've never heard of.
So you'd have to be a pretty hands off dad not to see it, even if it somehow wasn't noticed or reported to the parents by the doctors involved.
Edit: also, obviously fake and gay, forgot where I was for a second and was pretending it was real for discussion/entertainment sake.