I DM with a group of friends whom I've know since we were in middle school. We know eachother well so we all have a good idea on what's allowed and everyone respects that the DM while lenient, has final say in what's tolerated. That being said... The party artificer is notorious for messaging me with his crazy ideas and contraptions just 5 minutes before a session, and asking me to make a snap ruling on if it's allowed or not. I have enacted my retribution by afflicting him with wereraven lycanthropy, and over the course of a campaign have slowly transformed him into a bird man