Jerry "Mack" Mackinley was a builder who lived in Emmerdale for about a year in the early 2000s, during which time he embarked on a relationship with Diane Blackstock.
Mack and Syd Woolfe turned up in the village in March 2002, to work on Café Hope, the café Viv Hope was wanting to open in the village. Viv, who had recently been fighting with her husband Bob, instantly tried to make Bob jealous by turning on her charm. Mack later had a date with Diane Blackstock, and at the start was not too happy about Diane's plans for a relationship. After a talk about their relationship, Diane felt upset after Mack's rejection, but soon he regretted his decision, after Brian Addyman started to get designs on Diane, and tried to get back with her.
In May 2002, Mack moved into the B&B, partly to be closer to Diane. But later Mack started to get worried again, wondering if he and Diane were getting a little too serious with nights in. Syd, not to keen on the idea of Mack and Diane tried to break them up by inviting an ex of Mack's, Miranda, to go out with him, Mack and another girl on a double date.
After a serious of misunderstandings, reconciliation's and other things too Mack and Diane finally parted ways. Now free and single, Mack and Syd bet over which of them would sleep with Angie Reynolds first. Syd managed to sleep with Angie first. In 2003, Mack slept with Nicola Blackstock, after telling her that he loved her – just a trick to get her into bed.
Then not too long after that Mack moved in with Syd, Scott Windsor and Chloe Atkinson but was kicked out after Syd found out that Mack had been trying to take over his job. Edna Birch took pity on Mack when she found him sleeping in his truck. He took advantage of her generosity by taking her biscuit-tin savings replacing it when he got the first instalment on the village hall repairs payment from Jarvis Skelton.