1st time threesome possibility

My wife and I have been happily married for almost 9 years. When we were early in our marriage we talked a bit about fantasies and she assumed I wanted a threesome. I was honest and said that I was open to the idea but I'm also happy with our sex life and completely satisfied. She assured me she felt the same way, happy and satisfied, but she also said the thought of sharing me with someone else made her extremely jealous. At that point I was reassuring and supportive, and I never brought up the subject of threesomes again.
Fast forward about 8 years and one morning she says to me, "I had a really sexy dream and you were in it. That's not all, there was another woman also. At the time, I didn't pursue the subject or ask for details, but after a couple days I thought, what if she's trying to tell me something? My wife and I have never had a problem communicating with each other so I'm not afraid to bring it up with her. I just don't want to seem pushy or say anything that might lead her to think I'm no longer satisfied with her alone. If a threesome were to happen, I would do everything in my power to ensure she gets all her wants and needs met without any regret. So do I dare bring it up or carry on until she brings the subject up again of her own free will?