@tigersgirl -- If he wants you to work through your jealousy then he needs to do the same. Him saying he's ok with you being wih girls when you're not even attracted to girls is just nonsensical. It'd be exactly the same as if you said "Poly is fine, honey, but only if you only get it on with other dudes. Oh, and I get to flirt and have sex and maybe relationships with men too." I'm just guessing that that wouldn't go over well???
There are ways to work on jealousy, and the xeromag.com site mentioned above is great. But if you guys don't deal with this basic issue of fairness, I think it'll just blow up later down the line. I mean, how can you feel valued and secure when he's saying "This will be great, babe... I get everything I want and *you* get everything I want too!"