Police officers detain an anti-government protester during a demonstration inside a mall in Hong Kong on Sunday. (Reuters photo)

Unattached for more than two years, Joe, 30, was thrilled when he had a perfect first date in late August.

They connected on the dating app Bumble, met, and got along so well the Hongkonger, who works in human resources, thought he might be heading for a serious relationship.

Within weeks, however, it was over. She sent him a curt text message saying: "I don't want to continue any more."

Though disappointed, Joe (not his real name) guessed it was because he had revealed he was anti-police and "light yellow" - on the side of pro-democracy protesters, as opposed to "blue" pro-establishment supporters.

"I never thought my political views would get in the way of my dating life," he says.

With Hong Kong's anti-government movement now into its seventh month, singles seeking dates online have begun stating their political views, some making it plain they are not interested in people from the opposite camp.

"I feel that revealing your political stance has become a must on these apps," says Joe, whose Bumble profile now states that he is not looking to meet anyone who supports the police. "It's like we now have another filter."

Where people previously described themselves, the kind of movies or songs they enjoyed, or what they were looking for in an ideal date, more now state their political preferences.

Phrases such as "No blue ribbons" or "No yellow ribbons" are common on profiles. It is not uncommon to see protest slogans such as: "Add oil, Hongkongers." Some even post photos of themselves at protests.

The trend has caught on among users of dating platforms like Tinder, OkCupid and Coffee Meets Bagel, among others. Tinder was ranked first by Hongkongers for fame and respectability, according to a 2017 survey conducted by YouGov. It also found that four in 10 citizens used online dating apps, including almost one in two millennials.

Matchmaker Yubi Wong Ka-yu, founder of HK Romance Dating, which helps people meet face-to-face with no dating apps, is concerned about the latest development.

"People can be much less vigilant when someone claiming to be on the same side politically approaches them," she says.

As the protest movement intensifies Hong Kong's social divide, she says, young people tend to be more trusting of those who agree with them politically and that can lead to establishing a sense of emotional closeness quickly.

"Everyone can see your profile on dating apps, and scammers might make use of that to get to you," she cautions.

Looking back, Joe believes he got rejected because his date knew too many couples who argued over politics and did not want to end up that way too.

He says they discussed politics only when they met in person and, over dinner, she mentioned that she was "neutral" as far as the protests were concerned.

"But it was still quite a happy date, as we avoided judging who's right and who's wrong," he recalls.

They stayed in touch for another two weeks, until Joe posted a message on Facebook saying: "You should unfriend me if you support the police". He backs the protesters' allegations that the police use excessive violence when dispersing crowds, a charge the force denies.

His date was one of those who blocked him on Facebook. She then told him it was over between them.

Joe says he has been on dating apps for two years and used to care very little about potential matches' political views. He was more interested in their lifestyle, and whether they were heavy drinkers or had a "crazy nightlife".

While he thinks hooking up with someone who is a "yellow ribbon" like him will give them one thing in common, he does not believe political preferences should be the deciding factor, "as long as we agree on where to put it in the relationship".

Tinder user Ben (not his real name) says the first thing he checks these days is a potential date's position on the protests.

"If she's 'blue', I won't bother to chat further," says the 25-year-old university graduate.

Before the protests, he says, he assessed potential dates by their looks, hobbies and interests.

Now his profile reveals personal information and his favourite songs, but also protest statements such as "Liberate Hong Kong; Revolution of our times" and "This life, I will only marry yellow ribbons and frontline protesters".

"Having different political stances means we don't have shared values," he says. "It's better to let the other person know who I am at the very beginning."

Coming from a pro-establishment family, Ben tries to avoid confrontation with his parents.

"When I go to protests, I just tell them I'm out eating or shopping," he says. "With a 'yellow' girlfriend, I will have someone to go through thick and thin with me."

Yubi Wong, whose matchmaking company has about 20,000 members mostly aged between 28 and 36, says: "Stating political views used to be scarce on the dating scene. Very few Hong Kong people used to ask about that."

Traditionally, Hong Kong singles looked mainly for partners with similar income and education background. "Due to pressure from parents, such criteria were more important than having similar lifestyles or habits," Wong says.

She estimates that about 10 per cent of her clients now ask to filter out people from the opposite political camp.

In a sense, Wong adds, the rise of political awareness in the dating scene also reflects the city's strong family values.

"They think about establishing a family and how to educate their children. Many feel that this will go more smoothly if they know their partner's political views beforehand," she says.

Wong says she advises clients to avoid "sensitive topics" on their first three dates, and these include asking about previous relationships, religion and politics.

"The key is not to impose your view on the other, and try to find common ground," she says. "After all, love is about tolerance and understanding."

Frank Leung King-wai, a psychologist and counsellor, says love-seeking young Hongkongers always attached great importance to personality and values, and the ongoing protests have raised their awareness of checking on the latter.

"Political stance reflects one's logical thinking and how one judges what is right and wrong," he says. "So when huge social events happen, people have the chance to think about how different their values are, even at the early stage of a relationship. There is no way to dodge political discussion any more."

Discussing these matters can be a positive thing for those who are dating, and may even reduce the possibility of future conflict.

"When it comes to topics such as whether the use of violence is good or not, it is particularly hard to argue or make the other accept your view," he adds. "But if two people are mature and rational enough to find common ground, it can help them to grow closer."

Hongkonger Sulley, 24, and her Singaporean boyfriend Mike, 30 (not their real names) have had to work their way through these issues. They met on OkCupid this year and are in a long-distance relationship, with him visiting Hong Kong several times to see her.

Describing herself as "anti-police but peaceful, rational and non-violent", she says: "I knew that he had been in the army, so it's natural for him to be more pro-establishment. But I don't think it is that big a problem."

The couple recall getting into an argument when they were at Nathan Road in Tsim Sha Tsui one day, and saw police chasing a group of protesters.

Sulley, who had witnessed similar clashes, did not want to walk closer to the scene. "I am very non-confrontational, and I wanted my man to respect that," she says.

Mike, who happened to be wearing a black T-shirt, the colour of the protesters' garb, saw no reason to walk away. "I don't understand why you need to be afraid of the police if you haven't done anything bad," he says.

They talked about their disagreement later and were able to move on and even joke about it. "It's not like our personal views about the protest or politics define who we are," Sulley says.

Mike says that despite their differences, he never avoids talking about Hong Kong politics with Sulley.

"Being partners means you share about things, however complicated it could get," he says. "You just need to be patient enough, and agree to disagree. And that's how we click."