My ex and his wife

Hey everyone. So I’m in a pickle and I don’t know what to do. My ex BF of 5 years recently texted me complaining about his wife. He said that he’s working from home and that she’s always home, they don’t have any time apart which is causing a lot of fights. He said that he’s ‘lost his peace with her’ (idk what that even means?). Do I try and convince him that this is all temporary and things will be better soon, and that most married couples fight and it’s normal or what? Is it not my place to even meddle? Like honestly who am I? I wish he didn’t come to me for this because of our history. I kinda don’t care how their relationship is going but I just hate seeing people, in general, unhappy. I know him, he’s a nice guy, when we used to ‘fight’ I never heard his voice, it would never escalate into anything because he always stopped it. He’s a really really really calm person. I just can never imagine him actually arguing with someone. I don’t even know why he trusted me with this information. Why would he tell me he’s unhappy in his marriage and wishes he was still single? Can’t he speak to a guy friend or something. I don’t wanna be in the middle of all this but I don’t know how to tell him that with him being so vulnerable. I also want their marriage to work but I don’t want to be the one to help him through this because it might send mixed signals or ‘spark’ something. I just wanna ignore him but all I can think is sad puppy eyes.