I printed off and showed him all the responses I've received from this thread, I think he now understands that there's more to being poly than just having unbridled fun! However, although he agrees this is the case, he's still into the idea of some outer-marriage liaison, it will probably just manifest under a different title. Right now he's unable to accept that he can't have something meaningful (and spiritual) with someone else, which will include intimacy. Maybe he won't act this year but sooner or later I think he just won't be able to help himself - regardless of the pain it would cause me....because, as he said, "it's HIS journey".
It's only come to light recently, but this drama was all sparked by a particular woman at work, he invited her out for a drink and asked if they could be friends, they went for a drink but fortunately she got a different vibe from him and hasn't really spoken to him since (she told him she didn't need anymore married douche bags in her life!) even though he was adamant (to her) that he just wanted a friendship... she must have seen through him. He still feels that maybe they are "soul mates" because of the "energy" he still feels between them (even though they don't speak and she won't even respond to his emails!) So what "energy" could that be?....(I still think NRE)...
To think that he still had the nerve to come home and tell me that he'd met someone that he "wanted to go camping with, just as friends", because he thought he could learn a lot from her! "why can't a male and female just be friends?" he said)
I could sense he wasn't quite telling me everything, but I still helped him write an email to her the next morning as a damage limitation exercise! but this was before he admitted his true feelings for her about a month later (last week actually). Then it all made so much sense!
They will both be attending their work xmas party this Friday, so I'm hoping she still continues to give him the cold shoulder! I must admit, I will be super anxious until Friday night is over! He said he won't initiate any further conversation with her (ie: he is waiting for HER to see the light!) but you know how one can be after a couple of drinks!
In the mean time, I'm thinking about joining a poly meetup group anyway, just so I can understand it all better and hopefully learn from others how to deal with jealousy issues and a partner who feels love for another woman.