It's because he's chosen a temporary pleasure over long time relationship ( ̄へ ̄)there is no further answer to that. He might have been a green flag before but people cheats if they want to. He cheated because he's found a easier lady to hang on
For a man to change like that after marriage is actually weirdly realistic, happens all the time. They turn their own insecurities into resentment and blame their wives, they think being awful to them will bring back the honeymoon phase or maybe give them power over them. It's usually a power trip
I just saw it on tiktok that author is uplaoding again and we got to see the parents so right now what we need rn is translator please someone lick this up and translate there is around like 70 chapter now
I tought it was a yuri from the cover