Zayn, who proposed to Perrie in August, explained that he always wants to look his best for the Little Mix singer.
In an interview with E! News, he said: "I do try to impress her still, I do try to do a bit of exercise. I don't want to completely let myself go."
Perrie and Zayn are yet to make any definite plans in terms of their big day, but Perrie has hinted that the couple may be planning a Barbados beach wedding.
However, Zayn's bandmates have since been talking about his stag do, and it could get messy if the boys are left to plan the whole thing!
Liam Payne brainstormed some ideas, telling The Metro his plans to "kidnap" Zayn.
Meanwhile, Harry Styles suggested that Zayn should be put through his paces more than once. "We might just throw multiple stag dos," he confessed. It sounds like it'll be a night to remember!
Perrie first showed off her diamond engagement ring at the One Direction This Is Us film premiere in London, where she joined Zayn on the red carpet.
Their happy news was later confirmed by Perrie's mum Debbie, who gushed: "It's perfect and they get on so well together and understand each other. It's just fabulous."
Check out more stars who are engaged in the gallery below:
Copyright: Instagram Mark Wright