Male nudity is tricky currently. There may be some AIs out there that will do it, but my experiments so far have shown them to be MUCH more reliable with female nudity. Men tend to get depicted with female genitals or no genitals at all. The only reliable way around that seems to be starting out with a nude photo as your starting point, but that restricts story possibilities. Also, if you start with nudity, many of the AI photo editors won’t work with it.
The ban on adult material may be loosening:
https://www.msn.com/en-us/news/technology/openai-to-allow-mature-content-on-chatgpt-for-adult-verified-users-starting-december/ar-AA1OsNUk
Of course, that could just be a way of tapping into the adult market (you can produce your own bespoke adult content, we just need to charge your credit card $10 to prove you are over 18). Am I being overly suspicious?