I'm not sure if you were talking to Ari or me, but I am not suggesting you come out to all your co-workers. Confused a bit there.
The story helped. Its hard to get a grasp of what is going on for you without it for me.
Maybe a conversation that is along the lines of, "I have some good news and some bad news." followed by, "I want to be sure that you know that nothing for me has changed and that I like you very much." Then telling him you have a boyfriend and that you are poly and this is what that means to you and what it means to your boyfriend and what it could possibly mean to him if he should decide to get involved with you.
Anyone want to be friends on Facebook?
Send me your name via PM