Bisexual husband wants open marriage

I am a 34 year old woman and my husband came out as bisexual to me just under a year ago.... its been like learning who we are all over again... i sometime feel like he doesnt desire me anymore....but hes such a sweet heart and we have open communication.... i just feel like sometimes he needs to remind himself that he hasnt given me any attention.... we joke about cute guys together..... but there are times when i remember him saying he desires to be with them. And then my heart is crushed all over again.... after all ....going into this i thoight i was what he desired. Im very monogamous and dont think i could ever open myself up to another man in bed with us .... although he says hes holding out for the day i say yes to that... i told him flat out it would never happen. Its not that it doesnt turn me on, i am just VERY monogamous. I dedicated myself to him.... to him alone.... and i feel that a third party would just be a threat to our happiness.

I too have sexual attractions to the same sex which I told him some time ago (making him comfortable enough to come out to me i think) but i have no desire for another partner. This is what its like to be bisexual and monagomous..... he i think is bisexual and  wanting to experiment..... thats just my opinion... i know if i let it happen even once there would be no going back....and i would loose him eventually. He is going through a phase of wanting something he can't have....and i think everyone goes through that at some point in their life. If i open the doors...whats to stop him from never turning back...  we have gone through so much since he came out but the biggest hiccup was that he started hiding things from me as he thought it was awkward to talk about.... which made me feel like he was hiding something bigger.... weve been together for 12 years without me ever feeling distrust.... this is new and alarming for me...as it Changes how we interact on a daily basis now..... it so hard.... wish i had someone to talk to who actually knows whats this is like. All i have are my frienda who are on the "ill kick his ass if he hurts you" bandwagond and they have np idea how hard this is to navigate.... then there are those telling me not to be a prude.... lastly we have those who say it must bw so hard for him coming out like that.... try to be more understanding.... ive been so supportive so far... aside from opening my bed to someone else... what about me? What about what makes me happy...... can i even have that anymore of it doesnt make him happy.... sigh.... so confusing.