The 36-year-old soccer star - who has sons Brooklyn, 12, Romeo, nine, and six-year-old Cruz, as well as six-month-old daughter Harper with wife Victoria Beckham - explained while watching his brood grow up is a "great experience", it also terrifies him.
He said: "[Watching them grow up] is great but scary. Scary because I can see Brooklyn getting different interests. Wanting to go out with his friends, wanting to talk about girls, growing up into a young man."
However, David admitted he is glad he has three sons rather than three daughters, as he knows he will worry about Harper more when she grows up to be a teenager.
He added in an interview with the Telegraph magazine: "I must admit I would rather it be three boys than three girls.
"Well, by the time Harper is a teenager she's going to have three older brothers that are going to be, well, men."
David recently revealed he is still in awe of Harper because of how different she is to his older children.
He said: "I've obviously got three amazing boys and with boys you can throw them around and Harper is obviously my first girl and I'm more careful. Still now, I'm changing her diaper and I can't believe I've got a girl. Everything about her is feminine, the way she eats, the way she moves, the way she looks. I love having a girl, but I'm glad she's got three older brothers and a dad to look after her."