The 17-year-old singing sensation is to receive coaching from the soccer star in return for playing a show for the kids - Brooklyn, 12, Romeo, eight, Cruz, six, and one-week-old Harper - and says he will even bring girlfriend Selena Gomez along to sing. He said: "I`ve agreed to give the boys a private concert at their house - if David gives me some private soccer lessons. "David`s an amazing dad, and he told me how happy it would make the boys, so I had to say yes. "Maybe now they have a girl, Selena will have to come too, and dedicate a song to Harper. "David tells me my records are always played in their household, and David and Victoria are both really cool, so I`m happy to oblige." Despite Victoria and David saying their family is complete now they have a daughter, Justin thinks they may have another child in future. Speaking to the new issue of Closer magazine, he added: "David and Victoria are great parents, they will do anything for their kids. People thought they would stop now they have a daughter but I`m not so sure, they both love kids so much I can see them having one more."