Chastity and orgasm denial discussion

Has anyone dealt with a third party keyholder outside their marriage or relationship? My wife and I have very different libidos. I enjoy kinky things, while she isn’t interested in much of anything. She feels unable to satisfy my needs and has wondered if I’d be open to bringing in an external keyholder/dom rather than me adjusting myself. She also wanted to know if I’ve come across such setups before. My main worry is how adding a third party might impact our marriage while catering to sexual wants and fantasies. We’ve talked through these concerns, and we’re both receptive to the idea. I’d love to hear about other people’s experiences with this dynamic and how it influenced their relationships. Thanks for any insights!

P.S. The incoming keyholder would be a woman.