Friend is a conspiracy theorist- how to deal?

I have a friend who is dating a conspiracy theorist.

I’ve worked out that we smile and nod a lot during outings with them and then I come home and bitch to my husband. She’s worth the hassle and she’s happy so I’ll deal.

Is this just a talking point, just mindless entertainment, like reading the Astrology column and commenting on it? Or does he wear aluminum foil hats and insist you wear one too?

As long as it not affecting his day to day life, then it’s a harmless hobby.

Maybe if after they run down on a conspiracy theory if you just said something like “That’s just their cover-up. That’s what they want you to believe!”