She's definitely her mother's daughter!
"[Harper] gets her outfit ready the night before and then she gets up in the morning, we go down to get her ready and she changes her mind," the athlete, 38, says during an appearance on The Jonathan Ross Show airing Saturday.
He adds, "Then I’m in the room with Harper trying to pick out an outfit and anything which I pick out, which I think looks great, she puts back in. She's 2½!"
PHOTO: No Smiles Here! Baby Harper Is Just Like Mom Victoria Beckham
It seems the tot has inherited mom Victoria's love for fashion. In September, an alert Harper sat front row on dad's lap at the former Spice Girl's show during New York Fashion Week.
There's no doubt that the Beckhams have a full house with Harper and their three sons, Brooklyn, 14, Romeo, 11, and Cruz, 8½. And, naturally, the boys love to test their parents — especially when it comes to their baby sister.
"She went into one of the rooms the other day and they’re all giggling and whispering and I was like, 'What are you talking about?' And they said, 'We’re teaching Harper a joke,'" David tells Jonathan.
"I’ve heard some of the boys' jokes over the last few months and it's not something I really want them teaching Harper. I said, 'What joke is it?' And they said, 'It’s the elephant joke.'
"I said, 'You cannot teach your 2½-year-old little sister a joke like that! Thankfully, she doesn’t know the whole joke."
While Harper shares a passion for fashion, her older brothers are taking after dad when it comes to body art.
"[The boys] have already said they're having tattoos done. And I said, 'Well, be different, don’t have any tattoos,'" the athlete shares. "They said, 'No, we’re going to have one. We're going to have, "Mum and Dad."' So I can’t really say no to that."
Since David's retirement from professional soccer in May, he's been focused on his duties as a father, and admits he's spent most of his time in the car taking the boys to and from school.
"I’ve been lucky. I've always been able to take the boys to school in the mornings and pick them up and make them dinner. So I do even more of that," he explains. "I’m kind of like a driver at the moment, I'm always in the car."
And the doting dad has no problem doing that while Victoria continues to work hard and expand her fashion empire.
"Victoria's success has been really incredible," says David, who married Posh on July 4, 1999. "She's a great mother, of course, and she looks after the boys and Harper and that's our priority … but she works really hard."