I hope your right. I was fully supportive of her when this happened. She knows where I stand with Hotwifing so it’s kind of confusing for me when the subject never comes up anymore.
She told you before that she wanted you to take the lead.
You are her husband, the head-of-househhold, her provider and protector. She doesn't want to lose the security of that relationship. She doesn't want to see you as a wimp. You both fantasize mfm so Don't sit back and watch, you lead her and him in bed the first time. You pick a young stranger, no strings, tell him she wants youth, vigor and orgasms, several of them. He won't give you any trouble cuz he just wants MILF pussy. Tell him he needs to go several rounds, that way she's busy while you rest.
Don't forse her, but make some concrete decisions that she must follow. Tell her that this first time is just a test, you will both reevaluate afterwards. The consequences are ALL yours because you set it up, she will be blameless if it goes badly. Put this in writing as a promise.
Every family dynamic is different, I think you need to be the boss/leader to get her started. Use logic to overcome her emotion (fear).
Let her know you are excited but your rational mind is in problem solving mode and you are thinking clearly.