Non-monogamy?

I recently discovered that I would really like to have a daddy dom. My problem is that I’ve been in a very committed relationship for almost seven years. We’ve briefly talked about opening up the relationship because we’ve only ever been with each other, but I’m afraid to ask for what I want. I don’t want him to think I’m unsatisfied with our sex life. I just feel like I’m more interested in a BDSM-centered sex life than he is.

What do you think?