Former Hong Kong actress Rosamund Kwan joined Douyin in May 2021 and has since amassed more than 3.8 million followers.
Kwan, who turns 60 in September, is seldom seen in public, but she has shared snippets of her daily life, including the inside view of her mansion, on Douyin, the Chinese version of TikTok.
However, sharp-eyed netizens noticed that she follows only one person on the platform. And that is Hong Kong superstar Andy Lau, with whom she was romantically linked many years ago.
Lau, 60, was one of the first to comment when Kwan started her Douyin account, noting that she was on the platform at last.
The singer-actor does not follow anyone on Douyin even though he has more than 70 million followers.
Lau and Kwan are known to be good friends who have worked together on more than 10 movies over the decades. They have also played a couple several times, leading to rumours that they were an item.
The rumours ended after Lau and Ms Carol Choo married in 2008. They have a 10-year-old daughter.
Kwan, famous for her role as Thirteenth Aunt in The Once Upon A Time In China film series (1991 to 1997), was briefly married to Hong Kong businessman Chris Wong in the early 1980s.
She married Taiwanese businessman Pierre Chen in 2014 and they divorced a year later.