Percy: *shows All The Signs Of Being The Sea Dude's Child* Chiron: If I Can Ignore It Hard Enough Then It's Not Real - Tumblr Posts

I can't remember how much of this is implied canon or my own interpretation, but I fully believed that Chiron recognized Percy was a son of Poseidon from the fountain incident with Nancy Bobofit, knew that a child of the Big Three being claimed would be a total shit show, and simply chose not to say a word about it