Double penetration???

So me and my boyfriend of two years brought up the idea of double penetration....

Today me and my boy spent a great evening together and enjoyed each other’s company. Then somehow or another we brought up what we have been watching on porn. I told him what I have seen and he said he’s been thinking about something “but doesn’t want to tell me because he doesn’t know if he’s ready yet, if it’s a phase or not, or if he ever wants to do it at all.” My curious self pried it out of him and he told me “it’s just something I’ve been thinking about but I’ve been watching a lot of double penetration porn lately”

I was shocked and didn’t know how to respond and just straight up told him that’s not something I would be okay with and I don’t think I’d ever be okay with. I don’t like the idea of another man touching me let alone fucking me. And he respected that and said okay and didn’t push it or talk about it any further, but my insecure self continued talking and telling him how I felt and how it bothered me that he was okay with the idea of another man fucking me. He said I don’t need to worry and that it’s just an idea but it still is really getting to me.

Any thoughts? Should I be worried? What does this mean? Any comment will help, I really just don’t know how to go about this and don’t know wether or not I should be concerned.