Currently in an open marriage.
Was rocky at first as I'm much more of the monogamous type, but we have much better open, honest communication between each other now and things are going much smoother. Communication and honesty is IMPERATIVE. No bottling shit up as it only hurts oneself and everyone else involved.
Hell, even becoming BFFs with her new boyfriend (and it's just the one thankfully; not sure I could do more than that tbh.)
Plus it's kinda nice having the option to date someone else... even though I'm not actively pursuing it myself. If it happens, it happens if not meh.
Not to mention the perks of her not being around 24/7.
Gives me a little more freedom to do my thang in peace.
And the perks of splitting the bills three ways instead of just two so even more money for savings/investing & fun.
Definitely not for everyone though.