Ku Hye-sun posted recently that her husband Ahn Jae-Hyun spoke to other women on the phone even in her presence.
The actress also said she woke up early to prepare beef radish soup which he had requested for to mark his birthday. However, he took just a couple of spoonfuls.
Ahn, an actor, then told her that he was going to a party.
Now, pictures have appeared on Weibo that show the 32-year-old celebrating his birthday with other women in a restaurant, but without Ku, 34.
Ahn is seeking a divorce from Ku who has said that she will grant his wish, though the details have not been finalised yet.
The pair met on the set of the 2015 TV series Blood and married a year later.
Last week, she detailed their quarrels and differences in several posts, prompting Ahn to tell media that he intends to give his side of the story to put things in a better perspective.
Ku has asked Ahn to pay for his share of wedding and home-renovation expenses, and revealed that he told her that he no longer found her sexually attractive.
The Weibo photographs have led to condemnation from netizens who said such betrayal of a spouse's trust is unacceptable, even if the couple's relationship is rocky, and even if he could be hanging out with just female staff from his agency.
Amid the backlash, at least two companies - cosmetics brand Merbliss and fashion firm Giordano - are cutting their links with Ahn.
Netizens have also called for Ahn's dismissal from shows he is involved in.