Robert Pattinson already wants more children with Suki Waterhouse.

The 37-year-old actor and his musician/actress girlfriend Suki, 32, recently welcomed their first child together and Robert is so smitten he is eager to add to their family as soon as possible.

A source told "Rob has taken to fatherhood the same way he has taken his film roles, with complete seriousness and joy.

"He didn't know what it would be like but it's just blowing his mind. And to see how Suki has adapted and changed this soon since the birth has warmed his heart in a way that is unexplainable.

"Rob wants more children, and once Suki has the same idea, he is keen to try for another as soon as she is ready.

"They are having a really fun time being parents and it feels like second nature to them."

Suki confirmed the tot's birth by sharing a picture on Instagram of her cradling the baby.

She captioned the image: "Welcome to the world angel."

Although Robert and Suki - who are reportedly engaged - have kept their relationship largely out of the public eye, Suki previously opened up about their romance.

She told The Sunday Times newspaper: "I had two days off the other day, and it was like, no question I’m going back to see him. Then he’ll come out for a couple of days. I’m shocked that I’m so happy with someone for nearly five years.

"I'm always incredibly excited when I see his name pop up [on my phone] or even a text, and I think he feels the same about me.

"We've always got so much to say, and I find him hilarious.

"We always say that I never, ever would have thought I’d go out with a boy from Barnes and he didn’t think he’d go out with a girl from Chiswick.”