Was it all puppies and kittens or did you get any weird and wonderful stuff out of them? Did they even notice you weren't contributing? That would speak volumes I think.
I am not sure any man ever noticed that I was being unusually (for me) quiet. I did say things, of course, but more tidbits of smalltalk than anything substantial.
I suppose that's the normal way women are experienced to communicate.
Several guys admitted to watching porn (though they probably would have if I had outright asked them without sounding too disapproving?), but apart from that it was nothing more shocking than them letting it show that they weren't interested in me because of me, but just wanted some woman.
Which for me was a reason to rapidly lose interest.
There might also have been some weird political opinions and some unreasonable complaints about ex-girlfriends, but I can't recall anything that stands out.
The most shocking thing a guy let show to me was not when I was on a date but playing pen&paper roleplay games.
Apparently, dosing someone with a love potion, which results in a relationship and marriage, isn't rape. 
Not sure if he would have behaved the same if he was trying to get into my pants ... he did want to get into the pants of another woman in the group, so ...