So when flowers rub their gametes on passing animals in the hopes that those animals transmit them to other flowers, it's fine, but when I do it, everyone loses their minds???

I believe there's a good number of tribes near the equator that don't wear much, so not sure it's even universally NSFW, esp. if your job is a hunter/gatherer. But people wear clothes to protect from sun/pests/plants also. Would imagine we started wearing clothes as soon as we learned how, as it has many benefits, and then the sexualization came as a result of no longer seeing all the parts, and being curious.

For one, unlike most mammals, humans don't have fur that can keep them warm

Hermit crabs have entered the chat.

For me the problem is, with a few exceptions, humans are pretty ugly when naked. I prefer them in clothes.

The change happened when we lost all-over body hair.

Human have covered themselves from the elements basically as long as it was possible for them to do so

Well I don't think most animals have to worry about their outfit being safe for work since they're all unemployed freeloaders