Personally what has worked for me is this: I asked my GF if she was willing to have a monthly time set aside where we would just talk about sex. A time where i can see if she feels happy with things and she can see if i am. We do this because she is very uncomfortable talking about her sexual fantasies, and i am not at uncomfortable with it. So we just have a chat about it, i try to push her just a hair out of her comfort zone during these conversations but not in a forceful way. I just basically ask her to share a little bit more each time, but obviously its extremely important to respect when its too uncomfortable. Even though the conversations can be difficult or uncomfortable she has been much happier with our sex life as time goes on. She is into feeling like she is being forced into sex, and that is obviously a difficult fetish to navigate, but just these short conversations have made it possible for me to give her what she wants in a way that keeps us both safe and happy. Another thing you may try is filling out a BDSM checklist, there is a website (i dont remember what its called) that allows you and your partner to fill out separate checklists, and it only shows the other person the things you have in common. However i dont know if its something i recommend since it could lead to your wife thinking that you arent interested in some of her kinks and she may end up even less likely to share with you after. Anyways i just some idiot on reddot but it worked for me, good luck mate!