I think you have to ask yourself if you're actually ready to go poly yet or not. It sounds like not - it sounds like it's something you're doing to try and please her.
Hence you can just about cope with the idea of her meeting some random dude that she has no feelings for, but meeting her ex is a different ball game.
I've met quite a few couples online before where the guy is quite happy to see his wife getting banged by 6 guys at once, but gets a bit insecure if she's with one guy, and she seems to quite like him.
It just hits that nerve of 'does she like him more than me?'
To me, that is all jealousy is - the fear that your partner is meeting someone better than you are.
If you want to become truly poly (and I know that you should probably take my words with a pinch of salt, as I'm only just starting out on this road myself), then you have to start by fulling accepting that:
1) You are who are you are, and you have certain things to offer
2) Other people have different things to offer than you that your girlfriend might be interested in
3) That does not imply anything about your own value
4) There is the risk that one day your primary will find someone who she sees as a better match than you, and will want to make him her primary instead.
If you're not willing to accept these things, then you'll always struggle with the poly way of life I believe - because you'll always want to put limits on your partner. You'll only allow her to see the type of guys that don't make you feel insecure (ie the ones you feel you know you are better than). Guess what - she wants to see the ones that prod your insecurities - not to upset you, but because they are naturally going to be the most attractive guys.
Note that all of these 4) points still apply even if you're mono. There are still other guys out there, and there is still the chance she will meet someone else. Even if you get married and tie her down...that's still an illusion that you now 'own' her and she's fully attached to you.
You have to realise that if you really are truly poly, with no jealousy or insecurities, you are offering her something that 99.9% of guys cannot give her - that total freedom and lack of judgement. I doubt this is something her ex can offer. There's a decent chance that if you're fine about this, that he'll be the one who gets jealous and insecure, and turns her off...and she realises you are the one she wants.
However you don't do this as a tactic in order to make it happen. You just know that you're an awesome dude with something really special to offer. Some people will see it, and some won't. But don't try to force it...just put yourself out there as you are, and allow people to see it if they want to.
Now obviously she has to keep her side of the bargain. You are the primary, which means she has to respect you, and not treat him like the primary.
I guess the question is - what do you really want? I have a sneaking suspicion you just want this girl as a mono partner. In which case I'm afraid, she is probably not for you.
Last edited by ManofDiscovery; 02-07-2013 at 09:09 AM.