> Do these make me a pedo?
In the eyes of the law, likely.
> What about similar pictures my in laws have taken?
Yes, it's not advisable to take these kind of pictures.
> What about pictures of my young nieces and nephews doing similar things?
Yes, if there's nudity.
> Additionally, have you been around kids in bathing suits?
Not a problem.
> Sometimes the ones for little girls don't fit too well. There aren't exactly many curves to hold things in position at that age. What about accidental pictures of those mishaps?
Don't take pictures of kids in bathing suits.
Pretty much the rule is don't be around kids and don't touch kids unless they're yours, and I think everybody knows this today. And as a global rule, don't take pictures of kids at all, but especially avoid any that could involve any type of nudity, intentional or accidental (I'd avoid bathing suit shots for sure).
There might be a greater societal harm being done here, because as a male in my 20s, I have almost no interaction with children (which I think is fairly typical, at least among my peers). This could be a problem for my generation, as we're less likely to know how to handle kids; and it could be a problem for the younger generations as they don't get to interact with many adults besides their immediate family and friends. Either way, I think the societal rules about what's ok and what's not ok are reasonably well defined, if very arbitrary.
