I don't know and it's not my place to question but this was what he wanted! In fact he was almost insistent about it!!!!
"I want to watch your Sissy make you cum!!!"
I didn't need any encouragement and neither did my wife!!!!
The only thing was when she did cum he swept her up and carried her to the bedroom where he made her cum again and again and I had to wait here, on my knees, savoring her flavor and hoping I'd get a chance to, maybe, taste his cum too!!!!!