I've always known he's bisexual. Had relationships with men before he met me etc. We have a lovely sex life and I have no doubt he finds me very attractive. We're monogamous so to all intents and purposes his bisexuality has no effect on our life together except for the fact I know he sometimes fantasises about men during his, erm, private alone times. Which I'm fine with -- everyone has their private fantasies!
Is anyone else out there living happily with a bisexual partner? It's not something I really share with people -- my family don't know for example, nor do lots of our less-close friends. There were a few friends of his who were surprised when we got together as lots of people assumed he was "on the way to gay" 
I don't know if it's related necessarily but he is also very interested in gender equality and doesn't really have any hang-ups about his own masculinity.
So overall a positive experience, though I do wonder about our relationship being judged if lots of people knew he was bi. Would love to hear people's experiences of being in similar situations.