@Mangagirl07 I mean,
EDIT: Added the spoiler tag
Michi herself isn't coming clean with her infidelity. As of the recent chapters, it's still not clear if he is changing out of guilt or love. But the fact is he is constantly changing and supporting his Wife with most house chores and stuff. He was also seduced again by Mishima(glasses girl) in her house, but he stayed loyal and faithful to Michi while supporting Mishima when she was in need. He is constantly changing for the better. Yeah he cheated, but he was drunk. This is why i don't drink alcohol cuz you're prone to grave mistakes when drunk lmao. Niina came clean but cheated on his wife with full conscious thinking, and cheated with his heart and body. While You-chan cheated only with his body.