Two Pints of Lager and a Packet of Crisps - Season 5 Episode 7 Crab

It's the day of Jonny's and Janet wedding, and they're nowhere to be found! Gaz and Donna rush off looking for them. Gaz thinks he left Jonny tied to a lamppost, but the barmaid took him down. Jonny and Janet are stuck in a Tesco's van. They wake up in their wedding outfits, and have no idea why they're there. Meanwhile Gaz and Donna pretend to be Jonny and Janet, so they still can get married. Luckily, the Tesco van ends up at their wedding, and Janet and Jonny finally get married.