Thanks for clarification
I strongly believe that women need love, respect and safety/comfort. Suggesting her to blow a guy could decrease her self esteem, she could be afraid of being judged as cheap. But encouraging her to have full sex with someone means that she is adorable, she is wanted, desired.
Nothing I suggested to my wife for my pure pleasure (egocentric) was successful. On the contrary when telling her to do something which was 99% pleasing her - she accepted ... 1% because I enjoyed it and the rest because made her feel more sexually fulfilled and more complex.
Example is "I'd like to have a 3some for you darling, for you to feel two cocks, four hands, two tongues providing waves of orgasms..." Is ok but "I'd like you to jerk a guy while I watch" is not that appealing to women... To some women yes, but not for majority 🙂