As families across Hong Kong gathered to celebrate Father's Day yesterday, the Ng family were hoping that their temporary union will soon become more permanent.
Present yesterday were Ng Sing, 43, his father, 81 - who both live in Hong Kong - and Ng's older brother, 57, who lives on the mainland.
Ng Sing came to Hong Kong with his mother in 1992 to reunite with his father, who had arrived in the city from Fujian province 14 years earlier.
But back in 1992, his older brother was not allowed to join the rest of the family in Hong Kong as he was already married.
"We could only communicate [with my older brother] once every one to two months via long-distance calls," said Ng Sing.
"It was HK$9.50 per minute and it cost about HK$1,000 a month when my father's monthly salary was only about HK$7,000."
Today, Ng Sing's brother is forced to apply for a two-way permit to Hong Kong every three months to help look after his father. Each time, he must return to the mainland when his permit expires, to begin the application process again.
"My brother is still waiting for the day when he can really come to Hong Kong to stay with us," Ng Sing said.
His father, 81, now suffers from the onset of dementia.
"I hope that my brother can come [to live in Hong Kong] as early as possible. You never know how long my father can live," said Ng Sing.
Since April 2011, an immigration policy has been in place under which the grown-up mainland children of Hongkongers who were under 14 when their natural father or mother obtained a Hong Kong identity card, before November 1, 2001, are eligible to apply for right of abode.
In an RTHK Putonghua channel programme that was recorded yesterday afternoon, several other families with mainland offspring shared bitter memories of family separation.
Chan Yee-fei, head of service for NGO the New Home Association, estimated that there were still at least 50,000 grown-up children of Hongkongers waiting to reunite with their parents in Hong Kong.
The number that can come to the city is subject to the limit of 150 mainland migrants who are allowed each day.
"It still takes a long time before approval is granted," said Chan.