ObTopic
The topic you have to bring up again because someone went off on a weird, random rant.
'We were talking about the best pizza, and now it's about your weird obsession with your neighbor's dog's hair.'
'You started a debate about the best movie, and now it's about your weird uncle's TikTok dance.'
'We were discussing the game, and now it's about your weird habit of talking to your plants and your dog.'