I'm kind of wondering if the original poster is already past the point of not acting... after all he's posting that question here- that's a rather active thing to do...
I don't know what your relationship is to your wife- and you say that you are WORRIED about messing things up with her... are you in a faithful and solid marriage, or are you unfulfilled by her? To me that's the most important part of your posting. Don't screw up a good thing man, it's not worth it.
If you are in a relationship where, as your sex mate, she is completely connected to you, then she probably knows that you are conflicted and curious already. I'd say talk to her about it. She's the deciding vote.
Maybe she will tell you to get it out of your system. Maybe she'll suggest you bring a buddy home so she can participate. Without knowing your relationship, just playing the odds I'd give those two scenarios a pretty low chance of happening, but my point is that honesty is always the best policy- rather than doing it behind her back. | 
