I'd guess the fact that you are asking suggests you already have a pretty good sense of the answer.
...but now I want to know the details.
Make sure you remember to add the "Based on a true story" tag too.
As long as you tell the story in a poignant and respectful manner, I don't think there's a significant problem. But if you're still not sure about it, I think I'd just take this as a case study of sorts and write down what details you think make this a compelling conflict. Maybe look into other, more anonymous marital troubles and how they work, (there's no shortage of that shit on Reddit) until you think you've found the right bits and pieces to make something like this that is suitably your own creation. If your friend is, say, Richard Nixon, you don't have to write a story about watergate. But if the concept interests you, learning more about the politics of the time can help you fabricate your own watergate-adjacent conflict that's fictional enough for you not to offend your friend.
Well yeah with anything fictional even if you base it on something true you have to make things extra dramatic and exciting.
You've clearly already made up your mind and are just looking for people to tell you to do it so you don't feel like an asshole. Granted, I would have still said to do it so I guess the lesson is we're all assholes. What's annoying is you trying to hide your assholeishness behind this "guys is doing this wrong or not hehehe I'm a faggot" bullshit. Be a fucking man and do what you want to do instead of making retarded posts so you can feel better about yourself you piece of shit. Fuck you.
That's a long way to tell me I'm right
You're still at the point where your time and contribution to the site still leaves everyone here as more important than you. Context is important.
Like Mizal's red carpet dress