May take time

I sense that some on this thread have had frustration in convincing wives about their sharing fantasies. Well, the process of fantasy to reality, as in my case, can take time. I found that the vast majority of women equate sex with with the emotional bonding of giving to just one man in marriage. So, this is a wall that takes time to breakdown. Most of the time, not days or weeks, but months and even years.
My wife was raised very conservatively and with not much experience, so to introduce her to, oral sex, sextoys, anal, and sex in public places, parking lots and once in the outfield of a neighborhood little league park, with a chance of being seen became a huge turn-on for her. All of these steps were movements toward my, and by her free choice, goal of watching her taken by another man.
I'm not well endowed by any means, 5" erect. So, I bought an 8" strapon, top end and very life like. During a foreplay session of eating her pussy, I told her about and showed her my new "friend". When she saw it, she was leery about its size but was willing to try it. It took a few times before she was comfortable with it, and not much longer before she craved it. During our love making, we'd fantasize about who was fucking her. Well, long story short, it went to an amazing reality.
Don't give up on the "no's", keeping working, and the impossible can become fantasy fulfillment.