There has been nothing released to show Ann was pregnant but that in itself isn’t unusual. Women in the 60’s didn’t show their “baby bumps” like they do now, and living in Hawaii the clothing was an advantage especially with the mumus. On the other hand Jr’s close appearance to that of his grandfather shows that Ann was indeed his mother and passed on the Dunham genes. Remember that even on tv husbands and wifes weren’t even filmed in the same bed, they used twin beds. Fred and Wilma Flintstone broke down that barrier! As late as 1968 I can remember my mother commenting about how outrageous it was that one of my teachers was still teaching when she was about 6 months along.
I’ve heard others say they think that the maternal grandfather and BO look alike. I never saw it, myself - I think they were both tall people, but I don’t see any more than that. I guess, to me, it doesn’t prove it one way or the other. I’m not pushing for the hypothesis that he was adopted - I’m just considering the possibility that his being Stanley’s son might just be an assumption, not a fact. Or rather, it may be a fact, but we don’t actually have the evidence yet.
Well, my mom was pregnant with me in 1960, and she was also thin like Stanley. Pregnancy clothes are pretty obvious to spot, although I get your point about Hawaiian clothes - but the shape can still show. But mainly - even though they were both pregnant around the same time - there are lots of photos of my mom obviously pregnant, in maternity clothes. I’m curious that a birth a year later doesn’t seem to have produced any photos. Most women are really proud of their being pregnant and want to commemorate it with photos.