The TL:DR of the last post: wife interested in a guy we (mosly she) previously played with. We've always viewed this as a together thing but she expressed some interest in being solo, which made me nervous.

On to the Update:
Based on overwhelming feedback we discussed my concerns. We've always been very good at communicating and this is no different. I told her that I've felt a bit left out - our chats were always group chats and meet ups were always 3 people (she did have about 30 minutes alone with the guy prior to me coming into the room to let them get comfortable). She immediately said she would call everything off if I wasn't "enthusiastic in my support," which immediately made me feel better. She is not interested in an ongoing thing but maybe 1 or 2 times with this guy. Her biggest turn ons are the lead up and coming home - sharing her messages with me and then coming back for sex with me. She really has little interest in this guy personally - he is attractive, nice, clean, and safe. She knows what she is getting and feels comforable with him alone, which is the only reason she's into it. He is married (wife knows about this) and has another FWB so we aren't concerned about him or his motives.

So here is the big update: wife has to head to an event which is about 45 minutes away from where we live and he is about 15-20 minutes from there. They are going to meet at a bar for a drink or two on Friday evening after her event.

I've asked a couple of things from her: 1) overly communicate - i'd like to be on a group chat but i also know that it is often easier to get comfortable 1-on-1, so she is sending me screenshots of everything in real time because I enjoy it, 2) Ask for permission before moving forward with anything - I've never said no to her but I would like the ability to put on the brakes if I'm not feeling good about it - example is on Friday if she is really feeling it and they want to do more than just have drinks or kiss I'd like to be brought into that decision, 3) if there is anything borderline, take a pause and let her and I chat about it beforehand (this is mostly about sexual stuff - she has never expressed any interest in rough sex and if that comes up I'd like to discuss with her prior to her doing it with anyone else), 4) always be honest - if something is amazing don't hold back telling me about it because she is concerned about how I will react. If she is really digging something, I'd like to know even if I may feel pings of jealousy. I want to work through those together.

Thanks for the help from you all.