If you don't know by 21 that calling a woman a milf is degrading and offensive, you're never going to learn. Or at least not in any timeframe where it's valid for this company.
Ah, the good old "people's personalities are set in stone by 21" canard. If people were 'never going to learn', then first-wave feminism wouldn't have attracted anyone over 20, for example.
This kind of statement is just an excuse to throw a person under a bus, rather than take the effort to educate them.
> Or at least not in any timeframe where it's valid for this company.
And this is also nonsense. A simple talk can be enough. When I was at university, one of the professors kept asking improper questions of the female students, told to me by a female colleague. I went to my professor and asked what could be done, mentioned what my female colleague said (and stressed that she'd asked not to be named). My professor had a chat with the questionable professor, and the problem disappeared instantly.
It's called 'feedback', and we ask it of our colleagues, our clients, our trainees and trainers. Some people respond really well to feedback. For those that don't, well, at least you tried to improve things rather than kick the can down the road to someone else to deal with.
What is not acceptable is jumping to "MILF" or "DTF?" within a professional setting. Workplace courtship requires careful advancement with an ability to permanently halt at the drop of a hat. The recipient of an advance must always have full power. This new employee failed at corporate worker bee 101. He cannot be trusted with employees, customers, or clients. He should be terminated.