One day at December 1937, Semyon decided to hangout with Ivan and take him to walk around Moscow streets, after hearing Ivan had another argument and the wife shooing Ivan away from apartment to calm herself down. Ivan venting about stupid argument he had with his wife: about which trinkets that best for decorating the New Year tree celebration. Semyon listens and helps Ivan trying to understand Ivan's wife's perspective.
Later they passed by in one alley, Ivan wants to take a breath. And he is horrified to see Andrei and Maxim are having passionate kissing alone. Afraid to get caught because Ivan making loud gasp, Semyon immediately using his wind magic to fly away a bit, until they are in safe place.
Semyon then explaining; he has been knowing this since the ensemble perform concert tour at France around July-September 1937. He heard Andrei and Maxim have been indulging intimate sex behind the empty costume room or hotel room. Ivan demanding more explanation and the reason, and Semyon explained, "Remember Andrei's mother's death last year? Maxim is manipulating Andrei after that. He make sure to control Andrei, because his misogyny was that bad till he sought attention to men. That's why I don't want to interact too much outside of work..."
"But... but why don't you want to report Militsia?! You are key witness! You have the proof! Send Max to Gulag for good!" concerned Ivan.
Semyon waved his hand, "Will still be futile. Authority cannot see such difficult situation. They will thinking it's mere homosexual love. Both of them will be sent, and this will broke Dyusha further. Because looking at his condition now... Dyusha still believes that only Max who can save him. He can still pull the lie "No, I still stay single" if I try to confront. And I don't want to be slammed by him over such petty reason. I'll have to wait until his belief eroded, and by then... I will help him."
This horrified Ivan further. Reminded him about that argument over tree decoration. Reminded of why Semyon never joke too much when Maxim is around, while that accordionist can laugh with Alexei/Vitaly, Vadim and Stepan.
After Ivan escorted back to his communal, he entered the entrance door quickly. His wife who still sitting near the unfinished decoration tree glared at him, almost want to interrogate his whereabouts. But it seems Ivan's terrified face made her drop her glare and asked, "What happened?".
And for the first time, Ivan finally answered with half-truth, "I see a man sexually assaulting another man, and he almost going after me, too. I managed to run..."
The wife now looked concerned after being grumpy for one whole year, and tells Ivan that she will make sure to protect Ivan from assaulted by men, too. The New Year finally goes slightly peaceful than years ago.
And probably since then, Ivan finally more committed to listen better to his wife's insecurity. Although it's still hard to communicating and the marriage is beyond repair... but at least still maintained just for the children. And I think Ivan's divorce that happened in July 1945 is actually made the communication become clearer and everyone in the family able to heal better.