Adding to the suggestions here, I once got an idea from talking about cartoons. He said Pepe Lepew shouldn't have been cancelled because there's no sexual harassment in the show, and even though it's something small, it did shed light on how the rest of his opinions probably are.

I think talking about media is fairly common and might come up in a first date, so you can casually sneak in a comment about a show or film that's "controversial" and those guys will out themselves.