@skicoak I see what do you mean.
To show more clearly, why such doubts appear, let me provide an example of the last case, when I doubted, was it JUST humor or not quite. 
Once I discussed variety of things about society problems with my ex, and the subject of sex workers came up. Among the other things, I noted that prostitutes are very vulnerable part of society, both because they're despised and considered as "less humans" by many people, and because their work is illegal (in our country). I told, that when a prostitute comes to the home of a client, she has increased chance to be robbed, beaten or raped.
The guy told in response: "What do you mean by "rape" a prostitute? To fuck her and not give her money after it?
"
I had doubts, is it joke or not, because, as I already noted, dehumanizing sex workers is common. So I just looked at guy, trying to understand if he's serious or not.
He asked: "What now? Why are you looking at me, like I told something stupid?"
I told: "Because you really told something stupid".
After uneasy pause, I started to explain him the difference between sex for money and rape.
He told: "Yes, yes, I see. I was just joking, don't take it too serious".
If he would talk that it was a joke immediately, when he saw my reaction, I would not even remember this case. But these pauses made things look less than a joke and more like he told something between joke and what he really thinks and waited for my reaction, to turn it into more joke or less joke accordingly to it.
Of course, it's more than possible that all what I wrote is overthinking, I took his reactions too seriously and annoyed him by explaining him things he already understands well.
But if I have a suspicious, I think I'll better explain just in case... I don't think it caused him (or any other people in similar situations) any problems, except that they'll think that I'm tedious and take some topics too serious.
But I think I have a right to overthink this topic sometimes, considering my background 