Need advice

So here's the story.. I have always really enjoyed interracial porn and have the fantasy of my wife taking on a big black guy. I bought her a 8inch realistic black dildo to use in the bedroom. One of the ones with the suction cup on the bottom so she can ride it as she go's down on me and I get the pleasure of watching her slide up and down on it She wondered if I liked the idea of a threesome since I enjoyed watching her ride it. Because last time we did this I asked her how it felt to be taking on two at once. I asked her if she would be interested in possibly going forward with another guy for a threesome. Her response was "I wouldn't want you to want me to be with another guy". I'm not sure what to make of this, anyone have any idea what this means or have a similar situation? Not sure I would even want to go ahead with it if I could but curious of the concept/idea gets me going a little.