The Take That singer`s wife Ayda Field wants to start a family soon and he is getting ready to take responsibility for a baby, even though he is nervous about bringing a child into the world.
During an appearance on Dutch TV show `RTL Boulevard`, he said: "I thought that was part of the job. That`s how it goes, isn`t it? She desperately wants a child - I am terrified of that - I`m going to have to be [a good dad] and I will be because I will have to be."
Despite his reservations, Robbie thinks having a baby will be good for him and will make him less selfish as a person.
He added: "Yeah, I`m selfish. I enjoy doing what I want to do, whenever I want to do it. But on the [other hand], a baby comes into your life and you`re forced to not have everything be about you, and that will be good for me."
Before he has to devote himself to parenthood, Robbie is focusing on losing weight ahead of Take That`s `Progress Live` tour.
The `Kidz` singer and his bandmate Gary Barlow are having a weight loss competition so they are both looking their best for the mammoth run of concerts.
Robbie, 37, revealed: "Me and Gary vary in weight. We go up and down by the week. Gary and the boys were at my house in Los Angeles last week when Gary turns to me and says, `I won`t be needing these clothes soon, do you want them?` - because he`s going on a diet.
"That was the day I thought, `Right, if you`re eating a lettuce, I`m eating half a lettuce.` "