I finally really listened to that phone call - apparently Chris is dating someone else? Fiona?
I'm sure it's just another troll or one of his hundreds of imaginary spouses... but while we know incest has always been in the back of his mind, I can't help but feel that trolls are (once again) a part of this coming to be... the person in the call, for example, seems only too happy to push for incest relations. Chris has been swindled out of money, has been forced to shove sharp bits of model clay up his asshole, and has done several other things under troll guidance... this honestly wouldn't surprise me given that he was already keen to the idea.