Lol what're you talking about?
The exact reason why he teared up at the end is because that's the moment it all added up. He realized his friend's feeling and the pain he put him through. That doesn't mean he loves him back. He just cares for him that much. For you to disregard his relationship with his long-term girlfriend is much worse.
He doesnt regret marrige but instead feels sympathy and guilt because he realised he started and ended the romantic feelings of Kami even though it was one sided. He cried because he felt bad, yes, but it wasn't because he regretted his own marriage. As you can see he clearly wishes kami for his own happiness as he cannot provide it for Kami. He chose to stay as a friend because he still cares for him but can't love him back that way. Have you never heard of platonic love? Not all love are romantic or family-orientated.
You really expect him to be divorced by the woman he loves, someone he chose to marry over Kami's one-sided love that he always considered as friendship until he realised?
(Collected)
Woman break up with him so that I'm happy to see that person who makes speech be together with the man he loves.and I think your husband is willing to be with him.