Wife secretly interested in a threesome?

So Wife(30) and I M31 have been together forever and I've always made jokes about having a threesome. She always gives me a hard no and tells me I'm crazy. But then lately we both were a bit tipsy and chatting, and I asked her what her favorite porn to watch is. She answered immediately that it was threesome videos. That's her fav. So is that a deep subconscious desire of hers or just coincidence? And how do I get closer to asking that question? Now my mind is running dirty and wild thinking about it. And we have been sending threesome porn videos back and forth to each other saying specifically what things we like or don't like about it... Can't wait for the next chapter of this! Also any advice from anyone on how to bring it up? Especially girls who have been in her spot from her perspective?!