The mother-of-five told Fabulous magazine things had never been better with Kieran, after she forgave him for having an affair with her close friend Jane Pountney.
Katie, 38, said Kieran's organisation skills and ability to successfully run the household led to the 'grandad' nickname.
"He does everything, including the cooking and decorating. He's the type of man that if you're going out for the day, he'll have the baby bag packed. He's so organised that I don't even have to ask. I take the p**s out of him all the time and nickname him granddad because although he's 29, I act younger than him."
She added: "We need each other, which is good, and it wouldn't work unless we were together. We're a proper team. He does all the school runs, gets Harvey up in the morning and then we spend the day doing the horses and the animals together, unless I'm working."
Katie was devastated when she found out in 2014 that Kieran had been sleeping with pal Jane behind her back. It started after Katie gave birth to the couple's first son Jett, and was carrying on when she discovered she was pregnant with their daughter Bunny.
After initially vowing to divorce Kieran, Katie did a U-Turn and took him back, standing by him as he entered therapy for sex addiction and turned his life around.
Since then, Katie - who married Kieran in 2013 after a whirlwind romance - has frequently said she trusts Kieran and believes the whole incident has solidified their romance and made them stronger.
"I've got the Kieran back who I fell in love with, my Prince Charming, not the demon he turned into when he was with Jane," she told The Sun on Sunday night year.
"Everything in our relationship has got better."
Katie Price: All you need to know in less than two minutes!
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