He caught you stealing his future offspring.
As children are most vulnerable, you should separate him in a wire cage or dog crate until you make up your mind and invite him to dinner.
Aggressive roosters attacking children are the most tasty.
To me it seems too late as this has been going on for a month already: https://www.backyardchickens.com/threads/my-rooster-is-always-attacking-me.1439817/post-23866311