Go up the chain of command with the text.
Confront it right away, but not aggressively. You don't need to be aggressive because your boss will be so embarrassed, and afraid of you making a complaint about him/her. You can also let everyone know who you are, and respond to the text. Infact this is the better way to do it... you should do that... but MAKE SURE YOU REPLY ALL!... Not just your boss. You will regret it if you only respond to your boss.
Take it to upper management. That is BS.