As the crowd surged indoors shortly before 6.30pm, Luke Wassell and Lewis Jones found themselves in the vegetable aisle, wedged between the sweet potatoes and the bags of spinach. Though both are gay, they are friends rather than partners, and so “I guess I’ll have to kiss a vegetable,” said Wassell, glancing around him for a suitable candidate. “We’re definitely supposed to kiss something.”

The two students were among a gathering of hundreds who swamped a Sainsbury’s store in Brighton on Wednesday evening for a “big consensual kiss-in”, staged in protest at the treatment of two women who were threatened with ejection at the weekend after sharing a “very light, brief kiss” in the aisles.

People make their way into the store for the #BigKissIn

“It’s 2014, in Brighton,” said Jones when asked why he had wanted to come to the protest. This was maybe the sort of thing he might expect in his home town of Southampton, but in Britain’s most gay-friendly city, the incident was “ridiculous”.

He was not the only person who felt, in the words of one protester, that the store security guard had “picked the wrong town” when she told the couple that another customer found them “disgusting”, and asked them to leave if they continued to show affection.

The incident, said Fiona Spechter, had “made me realise how I can take it for granted that I can hold my girlfriend’s hand in public. I’ve lived in Brighton for a long time and it’s normal here, so when something like this happens, it’s really shocking.”

Still waiting for the kissing to begin …

Sainsbury’s has apologised for the incident, which it says “should not have happened”. The guard was not employed by the store directly but by a third party, it said, stressing that Sainsbury’s itself is committed to diversity.

The supermarket giant was taking a determinedly relaxed attitude to the event, insisting it was “happy to welcome” the protesters to the New England Street store. “We’re pleased everyone had fun and we were happy for the chance to remind everyone just how important being an inclusive business and employer is to us.”

Those few customers who had managed to squeeze inside past the crowds also appeared untroubled by the event, though most confessed they had no idea what was going on. “They’re all right, I’m working round them,” said one older woman, pushing a trolley laden with bacon, bread and a multipack of mineral water past the cheese counter. “Live and let live is what I say.”

Let the kissing commence!

“I’m more annoyed about the fact there aren’t any more large skimmed milks,” said another shopper, who gave his name as Sam.

But with the aisles packed with noisy couples and groups of friends, most waiting to be told to start snogging, a few breaking off excitable chats to kiss, the store manager, Enda Costelloe, confessed he was concerned about safety. A representative of Sussex University’s student union, which organised the event, was given access to the tannoy. “Right everyone, we’re going to do one big kiss and then can you all leave please?” he said, before counting down from 10.

Leaving the store minutes later, her shopping in hand, Sonja Turner said a member of staff had approached her to apologise for the disruption, but that she had told her there was no need. The store, she said, “don’t get it. It’s been the best shopping experience I’ve ever had.”