I had a handful of double sessions - maybe four... five - over they years. But they were all with trainees and I was requested/ordered to do so by Mistresses I knew. I was complimented they selected me, all the sessions amounted to half with the Mistress & trainee, with the second half being "finished off" by the Mistress alone. And in all of the sessions I didn't pay extra, a perk for me/doing the Mistress a favor, take your pick. The second half of all those sessions were the best.

The only double session I planned and paid to do was a fetish/vanilla scene with my Mistress commenting on my performance with our guest and her. The vibe was off and, while I may be an exhibitionist, I like it best just one on one with the Mistress. As the old line goes, "Two's company, three's a crowd."