But they do not reveal their surnames for fear of inaccurate snap judgements about "which side they belong to".
So deep-rooted is sectarianism in the city that a surname, the school you went to, the colour of your jumper and, most obviously, the football team you support, can put you in the firing line without even uttering a word.
The anti-sectarianism youth workers with Aberlour Youthpoint face these challenges every day.
Sectarianism is a can of worms, they both admit, and it is not going away.
Rather, it is being driven indoors in a "sinister" twist as the slurs and derogatory names used against Protestants and Catholics become less socially acceptable.
But Paul and David feel the years of ignorance have done nothing to stamp it out, so the time has come to talk frankly about it.
They believe that key to this is directly addressing the language.
They say the more words such as Hun and Fenian are used around children the more acceptable they become in their impressionable minds. And as violent attacks are often started by verbal exchanges, they believe the slurs are the root of the problem.
The youth workers, based in Govan, have developed a questionnaire for children that tests their use of sectarian names, how acceptable they think they are, how often they hear them and where.
They are also asking parents to get involved.
Questions include: 'Where do you see sectarian behaviour?' Those taking part are asked to circle and answer, with options including 'When applying for jobs', 'At school', 'On the street' and 'At home'.
Another asks the participants to circle the words from a list that they feel are sectarian. The options are: Hun, Tim, Billy, Fenian, Orangeman, Bhoy, Blue Nose, Tarrier, Loyalist and Republican.
Paul says: "In the past there have been moves to tackle the issues but with a tendency to skirt around the language.
"Some people do not understand what sectarianism is, although they are familiar with and use these words.
"We need to connect the two in their mind.
"If you tell what you think is a "harmless" sectarian joke in your home and your child overhears it, they could go to school and repeat it and end up getting suspended."
The anti-sectarian workers have circulated 100 questionnaires to children in schools in the South Side and also to their parents.
All pupils have returned theirs, but only 12 parents have.
At a recent meeting organised to bring parents from a non-denominational school and a Catholic school together, only one set of parents turned up.
David says: "We can't get to everyone, and some adults are so indoctrinated that they will never change their minds.
"They only ever hear one side of the argument.
"Then you get those who ask what you do and when you tell them, 'I am an anti-sectarian worker' they say 'I don't know why you try pal, you'll never change it'.
"But I am sure people said that about racism in the 1970s. We have to stop making excuses."
The duo say the younger generation is key to stamping out the problem.
Paul says: "We are using children to educate their parents.
"One of the questions in the survey asks school pupils what can be done to tackle sectarianism in Scotland.
"One wee girl said to us, 'I can do it, I can stop it'. It was a real breakthrough moment.
"Another girl innocently said she thought an Orangeman was someone who wore too much fake tan.
"We have also had children who say that sectarianism makes them feel 'angry', 'upset' and 'sad' in response to one of the questions."
But some of the children Paul and David work with are already showing signs of having been influenced by others.
David says: "Colour is a big thing. On one side you have those who wear green and would never, ever, wear blue and then you have the opposite. It is hard wired into them.
"We once had a seven-year-old girl refuse to use a piece of green card during one of our workshops."
Sectarianism is now recognised as a cultural problem, not necessarily a religious problem and not exclusively a football problem - Rangers and Celtic have not come head to head at senior level in almost two years and both teams have been working with fans and young people to tackle sectarianism - although football is used as an outlet for many.
It affects people who make up sects of the same religion, but many of those in Glasgow who would consider themselves Protestant or Catholic do not attend church.
David and Paul say that they are recognised as "cultural Catholics or cultural Protestants".
They are both keen to point out that sectarianism is also not just a Glasgow problem.
David says: "It stands to reason that as Glasgow is the biggest city in Scotland there will be more instances.
"And there are some bad examples here.
"There are still parts of the city that are considered to be one side or the other.
"During Old Firm Games there were separate waiting rooms in the A&E department at the Royal Infirmary for Celtic and Rangers fans.
"But there are 44 anti-sectarian projects taking place across Scotland and we have met workers from the north to the Borders and the East Coast - the problem is countrywide."
In December 2011, the Offensive Behaviour At Football And Threatening Communications (Scotland) Act 2012 was passed, criminalising behaviour that is threatening and hateful at a football match, including singing or chanting.
It also criminalises the communication of threats intended to incite hatred, including on social networks.
But it has been criticised by some supporters who say the sentences handed down to those convicted are too steep.
Paul says: "People have realised it is not socially acceptable to use these names and phrases in public.
"It is not as open as it was previous years, which I think makes it more sinister. It does not mean it is going away."
Aberlour has been given funding by the Scottish Government to carry out the anti-sectarian work until next year.
As well as collating the evidence from the questionnaires, the project is running educational workshops with school children, including a football programme that has input from Rangers and Celtic.
Workers also spend time on the streets with teenagers and support them into work placements and skills workshops.
David says: "There is a lot of positive work going on and we are hopeful it will make a difference."