Threesome

is it every guy’s dream to have a threesome?? my bf said he would want to and is curious about it but knows I wouldn’t like it so would never ask. I felt a little jealous but am I being unreasonable if that’s just some kinda dream that’s normal for some people? is it too high expectation to want him to just want me even in fantasy?? pls don’t be rude ._. I just have insecurities.