I learned a NSFW animal fact the other day. There are some fish that care for their young by holding them in their mouth, it's called mouthbrooding. That's not the new or NSFW part though.
The NSFW part is the fact that
for some fish, the fertilization occurs in the mouth. The female lays her eggs and scoops them up into her mouth. Then the male fertilizes the eggs directly in her mouth. Yes, it is exactly what it sounds like. A male fish cums into a female fish's mouth, and that's how they normally reproduce.
Ahh, nature. So beautiful. So like us.