It seems that adult content regulations have been tightened, but I don’t think it’s a bad thing to create adult content if you’re over the age of 18. Isn’t it good to use only with age authentication?
Consent.
It’s not good to do anything which the other party does not consent to.
OpenAI does not consent to you making sexual content with their model so, no, it is not good and is, in fact, bad.