I don't are what he does. So long as he is happy.
Sounds like a fairly dangerous way forward to me.
If he decided that he would be happy, maxing out the cards, taking out debts in your name, selling all off your possessions, including the house, pushing off to Las Vegas and gambling the whole lot away, leaving you with just the clothes you're standing up in, you'd be okay with that as long as he's happy?
But then again, I think you're one of those guys (wiped out the original term) from the porn sites, albeit slightly brighter and more tenacious than the rest. Why? Because you have lit this fire and bogged off. Instead of discussing what you would do, why you think this is the way forward for you, you have said that you're a woman who wouldn't care. I do not for one second get the feeling that you are a woman. Even if you do like PJ Harvey (easily Googled).
Personally speaking, I'm strictly monogamous. Polyamory is not my bag. I have 2 close non-sexual male friends and I find it emotionally exhausting trying to balance them. Can't think how I'd manage if sex were thrown in. That doesn't mean to say that I think monogamy's for everyone. If it's not your thing and everyone's clear about everything and happy with it, take it away.