Yes I have been with two husbands with the wife watching - reverse cuckold?
The meetings were arranged by the wife - they had normal cuckold where the husband watched and wanted to try the reverse. I was willing as one knew me and was happy for him to go with me and do as she asked to me. It was very enjoyable and we all enjoyed ourselves.
The other was a case when she told me of her husbands inability to please her - could I give THEM some hints. Show her? While doing it with him.
We had a couple of hours where we talked and engaged often and gave them both a few clues and suggestions.
I soon realised both of them were novices and had little idea of anything but missionary -she basically lay there until he came. Very little if any participation.
I virtually gave them a lesson in position play and how to use his cock and how she needed to respond. Between the three if us I believe I awakened them to how sex can be fun. To undress completely when having sex.
A month later she rang to tell me she now had had orgasms -before none -now regularly. She was so happy.
I was happy they found that sex can be exciting and entertaining.