My (31M) wife (30F) of 8 years has been spending more and more time with her coach and best friend (36M) who is also married. I'm having a hard time adapting to this new dynamic, and I'm in search of insights to help me cope.

Using a throwaway account given that she often browses Dating.mobi. I'm changing several details of the story and not using any real names.
​
First I want to preface and say that we are generally very happy. We love each other very much, and aren't experiencing any money issues. Of course, we both have disagreements occasionally, but never anything too serious. A little while before we were engaged, she experienced a very traumatic event in her life, which forced her to refocus her priorities and establish a new dream around which to anchor herself. I did my best to support her while she was going through this dark period in her life. Shortly thereafter, I started swimming and she joined me. Over the next few years we both got more and more into the sport, and that has become her source of inspiration, motivation, and her greatest passion. She really is quite amazing, and I cannot begin to describe how proud I am of her not just of her accomplishments in the pool, but in her resiliency as a person and a partner. She's truly a testament to the strength of the human spirit. Given our active lifestyle we have both managed to stay in great shape, and thus we are both still very attracted to each other and have a healthy sexual relationship.
​
All those things being said, she is also a staunch feminist and firmly believes (as do I) that women and men should be fully equal in society and no double standards should be applied. She deeply resents the patriarchy and its suppression of women. That being said, she also has self-admitted issues with authority figures and has been attracted to older men in her life that represent authority in the past. So, a bit of an internal conflict on that front.
​
Approximately a year ago, a new swim club opened in a neighboring town. They offered a variety of programs and amenities that could help her advance even further in her passion, and while I wasn't keen to leave our current gym, she was adamant that we at least check it out. We went out that afternoon to visit the owner, and we ended up joining later that week. During that first meeting, it was clear that my wife and the owner had very similar personalities and they hit it off immediately. They both had a deep love of the sport, and he was not only the owner but also a professional swim coach. She had a different coach at the time, but after being at this new gym for about 4 months, she started using his coaching services.
​
At this point I will mention that the coach/owner (let's call him Gabe) is really a very nice and genuine guy. He and his wife have been together a little longer than me and my wife. Over the past year, the four of us have started to hang out a lot. Going to dinners, drinks, dance concerts, etc. They really are lovely people, and I think we all get along well.
​
However, over this time period my wife has grown closer and closer to Gabe. They chat a lot over text or IM during the week, workout together on Friday mornings, go to a spin class on Saturdays, and on top of that they have gone on several overnight trips (sharing a hotel room) for swimming competitions. He coaches many athletes, and as my wife gets more and more into the sport she has begun helping him with his coaching duties. They have become best friends, with their own inside jokes. He often invites her over for drinks (his wife is home) when I'm going for a session at the pool, and they have also recently started recording music together. He also happens to share many of the same musical interests that she does. My wife is a guitar player/singer and he is a former music publisher. He has stated on many occasions that she is his "favorite" pupil, and he has nicknames for her. He makes her special dishes when they host parties (did I mention he is an amazing chef?), etc. etc. I have tried my best to be very understanding about all of these things. Like I said, I trust and love my wife and she should absolutely be allowed to have friends that make her happy.
​
There was one night however, that gave me a lot of pause about the nature of our relationship as a group of 4 friends. We were all out dancing at a bar one evening, and we were all quite tipsy. At around the 5th round of drinks and last bar of the evening, my wife makes a joke that she and Gabe's wife might go make out a bit on the dance floor. At this point I would like to say that I am a fairly open minded guy, but I usually draw the line at an open sexual relationship in a marriage. Always gonna be a non-starter for me. After she said this, Gabe asked me if I was alright with that (he's a nice guy, which makes it hard to demonize him), and I said my wife is gonna do what she wants to do since she's one of the most stubborn people I know. I took the opportunity to excuse myself and get some air. No kissing ended up occurring, but there were some other instances where my drunk wife whispered somethings in Gabe's ear (very loud music) and they had a laugh. Couldn't help but wonder what was being said. The next day I confronted my wife about the events of the previous night, to which she claimed she had almost no recollection given how drunk she was and that she was very sorry if she had done anything to make me uncomfortable.
​
I trust my wife. I love her with all my heart. At the same time, I am combating serious jealousy issues which I have desperately been trying to deal with. While it is true this guy is nice and married, he seems to be an expert on all the things that my wife loves. On top of that, he has a much more developed physique than I do. I'm no slouch, but the guy is pretty amazing. Over the past few weeks, we have fought about her relationship with him several times. I have not told her that I want her to stop being friends with Gabe, but maybe just spend a little less time alone with him. She already has so many activities that they participate in together, I just don't understand why she needs more. She feels as though I am being unreasonable and unfair. She claims that we would not be having these disagreements if Gabe didn't have a penis. On the other hand, I tell her that seeing her spend so much of her free time with a man who represents a high authority figure in her life's greatest passion, and who seems constantly shower her with affection and special treatment, makes me uncomfortable. The fact that she seems to prefer spending time with him over me, and that she continues to expand the amount of time she spends with him bothers me a little. It makes me feel as though I am an outsider. This is the first time we have dealt with such profound jealousy issues like this as a couple, and until now I thought that I wasn't one of those guys.
​
Well, that all came to a tipping point the other night when we had a blowout fight about it. The conclusion of the fight was essentially that she felt like I was smothering her, and that if I didn't give her the space she needed to spend time with her friend, she was going to end up resenting me and that it would destroy us. She stated over and over again how much she loves me, but that she is also her own person. I was heartbroken, but I could see that clinging wouldn't get me anywhere, and I had only one option to preserve our marriage. Shortly thereafter, she ended up leaving to go to his house to play music with him (his wife was home and hung out with them), while I went to my best friends house to have a beer and talk about things. After spending about 4 hours apart, I messaged her to let her know when I would be home, but my message remained unread. Another two hours later, I say my goodbyes to my friend and head home....only to find her car not in the driveway. It is now 11:30 at night and she has been over at his house for 6 hours. Neither Gabe nor Gabe's wife responded to my calls or messages either. I was experiencing simultaneous deep worry for her safety (late, I knew they had been drinking wine, deer on the roads, etc.) and pangs of panicked jealousy at her silent long absence. After about 30 minutes (which seemed like hours) she texts me apologizing profusely for missing my messages. She said she is heading home, and tries to call me several times. I can't talk to her at the time, and decide that now that I know she isn't dead in a ditch somewhere that I will just go to bed because if I wait for her to get home I know I will say something to start another fight. I slept on the coach of my own volition.
​
The next morning she was so distraught. She said she was so upset I wasn't in bed with her that she barely slept, and that she was so sorry for making me worry. We talked things over more, and despite the fact that we were both still upset and things were rocky, she left to go to the spin class with Gabe because "they had plans and it was too late to cancel". After she left, I felt extremely emotional. More so than I have in my adult life. I am not afraid to admit that I wept.
​
I want my wife to be happy, and to experience fulfillment not only in our relationship but also in her friendships. I don't want to be the person that holds her back. However, I cannot help but feel deep sadness that she chooses the good feelings she gets from hanging out with Gabe over my own emotional anguish. I think she expects that I will get over it with time, and that I will eventually be OK with the trajectory of their relationship. What happens if I can't? What happens if I can't find a way to deal with my jealousy and intrusive thoughts about the nature of their relationship, and she refuses to compromise on any aspect of her friendship with Gabe? My wife is the love of my life. Any insight would be appreciated.
​
TL;DR - Wife's greatest passion is swimming, and she has become best friends with her swim coach. She also has self-admitted issues with authority that occasionally result in her becoming attracted to male authority figures. They spend a lot of time together and have become best friends. Should I be jealous? If no, how do I work through my feelings? If yes, what do I do?


Source.