Catching up

My Wife and I are OLD and for most of our married life we made assumptions about the other, sexually. She is the product of a strict father and twelve years of Catholic schools. I was an only child of a single, working Mother until she found a really good man when I was twelve and yes, I was a spoiled little asshole. My Wife and I have had our problems over the years but for the most part we are in a good place now. She always thought "good girls" don't ask for or talk about sex. I interpreted that to be a lack of interest so that part of our lives remained low key. That changed over the past several years as I admitted to myself that I'm bi and she let me know she actually likes sex. I finally found the courage to tell her about my bi desires. Three or four years ago we met a young service provider who has become a good friend. Turns out he's happily married but his wife has a rather low sex drive while he's horny most of the time. I helped by providing him with oral when we could discretely get together. At the same time the Wife and I have tried to step up our sex play and she has slowly accepted that I enjoy oral with our friend. While the years of little sex have screwed me up and it's difficult to get "up" for her I've managed to orally please her routinely. Being totally open with her I decided to blow our friend while she watched and she admitted that was a turn-on, just as being stimulated by porn vids gets her going but she said she wants sex "just between the two of us". That ain't working when my instrument fails to firm "up" because my head, neither one, isn't in the game so the last time our friend and I played with her closeby I put his hand on her leg. It took my breath away as he rubbed her theigh and slide his fingers between her legs. She seemed to go with it and she was much wetter than you would expect a woman her age to be. I wanted to finish him and take care of her orally but she was too shy. It was obvious that she was turned on but she coudn't let hereself go in the moment. After years of a repressed sex life we WANT to catch up and enjoy what we missed, AND she deserves all the intense satisfaction of intercourse that I haven't been able to provide. Our friend genuinely likes my Wife and would like to get "in there" to give her those deep orgasms that she has missed and I want to see her shudder with sheer pleasure. I admit the fantasy of having him orally after is a huge turn-on but how do I convince the love of my life, who wants it to be just between the two of us" that what we share IS between the two of us? Our friend would be there to enhance the experience for the two of us. Am I just rationalizing my desire to see the dick that I enjoy so much pleasing her, for my own gratificsation? I probably should see a shrink to sort this out but at my age I don't wanna and I can't afford it anyway. Anybody want to share thoughts? Am I just being that spoiled kid again?