The police turned up on his doorstep last Sunday evening and asked to speak to his daughter.
Little did Mr Stephen Lo know that his daughter would soon be arrested for allegedly vandalising several roads by painting 'My Grandfather (sic) Road' on them.
The next day was spent fretting about his daughter, Miss Samantha Lo, 25.
She was released on police bail and returned home around 10pm on Monday night.
Speaking to The New Paper briefly at their corner-terrace home in the east, Mr Lo, a commercial pilot, said: "I had no idea that she had done that."
Miss Lo declined to speak.
Said Mr Lo: "She's quite traumatised and distressed by what has happened."
Miss Lo's uncle, Mr Kelvin Tan, 47, described her as a nice, humble, independent and sincere person. Miss Lo took art as a GCE O-level subject in CHIJ Katong Convent before going on to do her diploma and degree at a private school.
She started online magazine RCGNTN (pronounced as "recognition") three years ago, said Mr Tan. "She wanted a website dedicated to local talent. She's always had this wonderful desire to help local artists. She's very dedicated.
"And I'm upset because I don't think she should be treated this way. She was just trying to make an aesthetic statement."
He said: "Her art started with clothes, then she took it and developed it into another form of art - street art.
"I actually didn't know she had started doing street art. I saw the news but didn't realise that it might have been her."
Mr Tan, who has been teaching at the Lasalle College of the Arts for 10 years and is a musician, said: "I had the biggest shock of my life when her father called me."
He feels that the stickers are not an act of vandalism because they were thought through and well-conceptualised, but declined to comment on the paintwork she allegedly did.
Comparing the stickers to graffiti done on trains or the scratching of a car, he added: "As an art lecturer, I feel that she's trying to make a statement, and has carefully considered all the options.
"Right now, where art is concerned, all this is not going to be very good about how the country is going to perceive us (artists).
"Freedom of expression comes with responsibility. In the case of Samantha, it is irresponsible to a certain extent. But some aspects of art needs irresponsibility to work, to send the message across."
Mr Tan said he intends to speak to her today.
He added: "I think we should let her rest, and let her cool down. She's being hit left, right, centre with all the attention."
Unlike Miss Lo's father and uncle, though, some members of the art scene were aware of the stickers. Mr Yasin Rahim, 29, her fellow contributor at RCGNTN, said that she had been giving the stickers out for eight to 10 months.
"The stickers were very popular and freely available at RCGNTN events," said Mr Yasin, a photographer.
He added that it was unlikely Miss Lo put up all the stickers herself.