Would you consider a man in a park playing with little girls a predator? No you wouldn't, because that can be both a predator and a sweet grampa (and many other things). A man having a relationship (you are saying hitting on, you don't know) with a young girl is not necessarily a predator. Mind you, it can be! But the age alone doesn't tell us that. It's not nuance questioning, is accepting that human experience is different and people are different and yes, it's possible that a very young person has a very good relationship with someone much older. If I saw two people in public, it's not the first thing I would think, but that's due to my prejudices.

Also I don't care what two people say on a forum. The comment got 4 upvotes, so even the temperature check here shows me that it's clear I am not defending predators (which I would find abhorrent). Nor you nor anybody else has elaborated on why a middle-aged person in a relationship with a 20yo is necessarily (emphasis on necessarily) a predator. So I take it for what it is: a cultural item which is based on mostly prejudices and traditions. Mind you, I have it as well. This whole disgust is the first thing that came to my mind too. I just realized that it's based on nothing more than my gut feeling.

Edit: since I grew tired of having to receive sever accusations by people who refuse to engage in good faith in a discussion, potentially questioning their own moral value, I will give make you a favor and block you as well. Cheers.