Small groups of women, their hair freshly blow-dried, chat animatedly, while those who are new or have come alone hover self-consciously, waiting for staff to show them to a table.
At a Dates-n-Mates party there is no dress code; ethereal frocks and sparkly shoes jostle with sequinned two-pieces, brightly-coloured skirts and jeans and jumpers. There are no rules on the dancefloor either. As the band blasts out John Denver's Country Roads, voices are raised and arms fly out in all directions. A middle-aged man moves uninhibitedly to his own beat, his kilt flying up as he birls around. Somewhere in the middle of this riot of colour and noise, a young couple stand intertwined, the girl, as dainty as a china doll, on her tiptoes so she can gaze into her partner's eyes.
Those party-goers who are still single are coyer about their desire for love or a liaison. "I'm here to make new friends," says Karen Dreghorn, 33, who has been posing, hand on hip like a catwalk model (but with antlers) in front of a photographer in the foyer. Asked if she's spending the night in the Radisson though, she gives a cheeky grin: "I'd love to stay in a posh hotel if I could find a nice guy to stay with me."
Until the seventies, the concept of sexuality in people with learning disabilities was taboo. Often perceived as children trapped in adult bodies, the possibility they might have the same desire for intimacy as everyone else was scarcely countenanced. In institutions and in the community, men and women were kept apart, so any sexual encounters that took place were fleeting, furtive and unsatisfying.
Today, attitudes have changed; those who work with people with learning disabilities recognise the importance of socialising and dating. But even so, it can be difficult for them to find a partner. "There are lots of barriers," says Joyce Innes, project co-ordinator at Dates-n-Mates, the only organisation of its kind in Scotland. "It starts when they move from school into the care system and lose contact with people they have been friends with for four or five years. We find the longer they are not going out into society, the longer they lack the strength to go out and meet new friends, the more they are inclined to lose confidence."
People with learning disabilities may also lack social skills. Some find it difficult to grasp the mechanics of conversation or to make the jump from small-talk to asking someone out. So Dates-n-Mates runs workshops to give its 140 members the opportunity to hone their chat-up technique. Using role play, staff encourage those taking part to come up with a list of opening gambits such as "What's your favourite music?" and to remember conversations are two-way exercises. They also get members to think about what is and isn't an appropriate question on a first date. "We have had to discourage people from asking: 'What weight are you?'" Joyce laughs. The hope is the workshops will help them make the most of the agency's social events: speed dating, mix and mingles, party nights and club nights, which can provide the spark for a handful of romances.
It was at one of the club nights that Stuart Devlin and Nicola Hamilton met. Sitting next to her now-fiance in the Dates-n-Mates office, Nicola, 31, is chatty and gregarious, but back then she was still living at home and, with no job and few hobbies, spent most of her time holed up in her bedroom. When, egged on by one of her support workers, she turned up at the venue with her niece, she hung around the bar feeling awkward until Stuart, who was having his face painted, was asked to show her around. He took her hand, introduced her to his friends, bought her a drink and stayed at her side for the rest of the night. "My niece says we were kissing," Nicola giggles. "Then, as we were leaving, Stuart sent me a text saying he loved me. I've still got it on my phone."
Nearly two years on, the couple live together in supported accommodation in Castlemilk, Glasgow, with two dogs, a collie and a mongrel. The move was stressful for Nicola's family as she has haemophilia, but it seems to have worked out, with Stuart always on the look-out for potential danger.
Indeed, they complement each other in a way that makes independent living feasible. For example, Stuart struggles to make himself understood, but Nicola instinctively knows what he is trying to say and interprets for him. It is touching to hear her finish sentences he has barely started, as he looks adoringly on.
Having gone out with each other for 10 months - their first date was a night at bowling followed by dinner - they got engaged in a restaurant shortly before Valentine's Day last year. Stuart's brother helped him choose the ring and, having been let in on the secret, members of Nicola's family rallied round to make sure she looked her best for the occasion. Though Stuart, 32, says he was so nervous he couldn't stop twisting his ring finger, she didn't suspect a thing. "As soon as we got inside, he tried to take my jacket off and I was like, 'Give me a minute,'" she says. "Then he got down on one knee and I thought he had fallen over. He got the ring out, but I was in shock, so he was down on the floor waiting for an answer, but eventually I got myself together and said, 'Of course.'"
In the restaurant, nobody made much of a fuss of them. Nicola's mother had phoned ahead asking for champagne to be laid on, but none was produced, while someone else who was celebrating their birthday got a cake and candles. But the reception they received at the Dates-n-Mates Valentine's Ball a few days later more than made up for it.
The agency's first big success story, Stuart and Nicola were hauled up on stage as the DJ announced the news and their friends cheered and crowded round to see the ring. "I nearly burst into tears," Nicola recalls.
Now the couple are looking for work and saving for their wedding which they hope will take place next year. "We have talked about having children, but Stuart doesn't like to think too much about things in the future because it worries him so we have decided to take things one stage at a time," Nicola says. "The dogs are enough work for us at the moment."
Stuart and Nicola were lucky to find love so quickly. But for other people with learning disabilities - those whose social circle may be limited to those they meet at a particular day centre or be constrained by the number of hours they have access to support workers - finding the right partner can require a concerted effort. And, even once a spark has been ignited, more care will be needed to ensure the relationship progresses at a pace both parties are comfortable with.
After one of Dates-n-Mates' speed dating or mix and mingle nights, all those who have expressed a tentative interest in one another are invited on a group outing where they can continue chatting without the pressure of being on their own. Then, if both halves of the couple are still keen, someone from Dates-n-Mates will chaperone them on their first proper date, to make sure it all runs smoothly.
From that point on, they are left to get on with it. But the agency is on hand to provide moral support if problems arise.
"Sometimes, people will come to us a bit upset. Maybe they don't know what is happening with the relationship or it's all moving too fast," Joyce says.
"Of course, there have also been occasions when there's been an imbalance of affection and we say what you would say to anyone in that situation: that there are lots more people to meet, that there are plenty more frogs to be kissed."
When you look at academic studies into people with learning disabilities' experience of sex, the picture can appear bleak. The proportion who lose custody of their children is much higher than that of the general population.
And yet, the right relationship can revolutionise their lives, bringing them companionship and the confidence to take on challenges that might otherwise have overwhelmed them.
At their top-floor flat in Helensburgh, Paul and Pam McCann, who are in their sixties, are sorting out tea and biscuits. The ritual is played out as a graceful pas de deux, with much to-ing and fro-ing, clasping of each other's hands and playful poking as they fill the mugs and set out the Tunnock's teacakes.
Their living room is a testament to their 25-year relationship. The walls are crammed with photographs, college certificates, pictures of sailing boats and blossom-heavy trees painted by Pam, as well as souvenirs from Celtic - Paul's other great love. The shelves are heaving, too, with trinkets and shell-covered boxes and a figurine, which Paul points out as his latest gift to his wife. "I still like to surprise her," he says.
Paul can remember the first time he set eyes on Pam. On his first day working as a milk boy in 1967, he was sent into the baker's her father owned and she was serving behind the counter. Though they didn't meet again for 22 years, he recognised her straight away when he moved into the sheltered housing complex where she was living. Struck by her "lovely smile", he decided it must be fate and bought her an engagement ring on Glasgow Fair Thursday, 1990, a date he remembers because it was the only time he got three weeks' wages at once and could afford to splash out. As for Pam, she reckons she fell for him at a house-warming party. "He [the host] had a CD of Scottish music and it was playing Cock Of The North," she says. "But I was singing different words about Auntie Mary and a feathered bird and I looked Paul up and down and we were laughing."
Yet despite their obvious bond, the couple had to fight to be allowed to go out together after cautious support workers tried to thwart their love affair. "Oh, we were doing great until they decided to stick their tuppence-worth in," says Paul. "They were suspicious. They thought I was up to no good." Determined to stay with Pam, Paul confronted them and eventually won them over. Even when the pair were told they could move into their flat in 1995, however, there was no sense this was something to celebrate. "They left me to lift all my stuff over the bridge," says Pam, still smarting at the memory. "I had to carry a chair and four trifle dishes. I went flying down the stairs and two of the dishes broke."
The setbacks did not end there. Their wedding had already been put on hold while they did up the flat. Then, once they were settled, Pam dropped a bombshell. "One day, she says to me, 'I'm not sure if I'm ready to get married,'" Paul says, "and I said the most romantic thing I've ever said. I said, 'Don't worry, hen, I'm not going anywhere.'" In 2005, Pam decided the time was right, and, dressed in a blue suit and big hat, she stood in front of the altar swinging Paul's hand back and forth in time to the music.
You only have to look around their home to see how full their lives are now. Paul helps spreads the message about their marriage and recently spoke at a conference called Undateable? Not Me! chaired by Scottish Consortium for Learning Disability chief executive Chris Creegan. As well as making things, Pam loves to go dancing and shows off her beautiful dresses, holding them up to the light so we can admire the material and the beading. They go on holiday together too; they spent their honeymoon in Ostend but they've also been to Ireland and Lake Garda. They travel on organised, but unsupported, coach trips, mixing with the other passengers and, if they are lucky, being given a bit of extra attention from their favourite driver.
It is this level of independence that Dates-n-Mates is striving for. The hope is, Joyce says, that in five years' time, the agency will have made itself redundant as people with learning disabilities join the same dating agencies as everyone else.
In the meantime, however, many of its members will continue their quest to find "the one" at the Valentine's Ball at St Andrew's on the Square, Glasgow, on Thursday. Taking the first step to getting to know someone new is daunting, but as the McCanns have discovered, when the chemistry is right, it can be life-enhancing.
Asked what being with Pam means to him, Paul looks as though he's going to struggle to express himself. Then his eyes light up. "One time, during an evaluation, I was asked: 'What makes a perfect day?' I answered: 'Every morning, when I wake up next to Pam and I think, despite everything, despite all our health issues, we are still here and still together.'" n