Dulcie Froggatt met Jack Duckworth when he washed her windows while on his round in December 1984. He'd been having a terrible time since taking on the round but ended up spending the afternoon with an appreciative Dulcie in her house. Two weeks later, he called again expecting second helpings but Dulcie's husband Ralph answered the door. Ralph had his suspicions that Dulcie had a bit on the side and Jack had to clean all the windows in Cromwell Street to convince Ralph that cleaning windows wasn't just a cover.
Jack and Dulcie carried on with their affair and managed to hide it from Ralph and Jack's wife Vera, although there was a close call when in October 1985 Jack fell off his ladder while cleaning Dulcie's windows and was nearly caught with Dulcie by Vera. In 1986, Jack sold his window cleaning round but still met up with Dulcie, on one occasion entertaining her in Vera's car. Jack found a pair of men's briefs down the back seat and realised Vera had been playing away.
In February 1987, Terry Duckworth called at the house when he was selling household goods door to door. Dulcie took a shine to him and, with Ralph away, invited him in. Terry had no idea she was Jack's fancy woman and lapped it up, returning for more the next day - but Dulcie had to rush him off when Ralph came home from work early. Dulcie tried to bluff Ralph but he'd seen a man and asked her if she was "up to (her) tricks again", to which Dulcie became emotional and distressed. Ralph did some investigating and, finding Terry's van outside the house bearing the name "Duckworth and Watts", assumed Jack was the man he saw and punched him in the Rovers in front of Vera. To avoid being thrown out of No.9 by Jack, Terry admitted to Vera that he'd slept with Dulcie, and Ralph Froggatt had got it wrong, but when Vera stormed over to the Froggatt residence to have it out with Dulcie, Dulcie told her to keep her randy husband and son away out of her life, causing Vera to realise that they'd both slept with her. Jack managed to lie his way out of it, claiming he had quit his window round because Dulcie had made unwanted passes at him which made Vera feel guilty for doubting her husband.
Jack and Dulcie didn't see each other again but Dulcie wasn't forgotten. In 1994, when Jack made the newspapers for camping out on No.7's roof to rescue his pigeon Fergie from Curly Watts's observatory, Dulcie told reporter Malcolm Eden about their affair and it made the national papers, to Jack's horror. Jack spent the day making sure Vera didn't see a copy. He succeeded but Vera found out anyway when she bought fish and chips were wrapped in that day's paper. She announced her intention to sue the paper as there was no way Jack could go five times a night!
In October 2010, when Jack had been diagnosed with Non-Hodgkin's lymphoma and was thinking back over old times, he joked to Tyrone and Molly Dobbs that he was going to see Dulcie.