Nice. Many of us have learned that a more nuanced approach is more likely to work, assuming the interest is there. You are already "out" as far as what would turn you on so just it ride for a while. If your wive perceives you are mounting a campaign (asking her to watch bbc porn, buying black dildos, showing her cages, talking about it every time you are in bed, etc.) she's going to feel pressure and that will not have a good outcome for either of you! Wait for her to give you a cue. You've been pretty forthright in what you said to her thus far - I'm thinking she'll be thinking about it. I love that your marital relationship is foremost in her mind. That's not worth putting on the line if she doesn't want to go there. You have to live out many more years together.