WATCH | Prince William welcomes Baby Sussex with classic dad humour

Prince William who shares three little Cambridgers with Kate Middleton knows the joy and maybe, the sleep-deprivation of a new dad a little too well. After all, haven’t we all seen the Duke of Cambridge trying to stay awake in one of the press conferences? Apparently, ‘sleep-deprivation’ is the first thing that came to the Prince’s mind when Meghan Markle and brother, Prince Harry welcomed Baby Sussex on Monday.

Responding to the royal birth, the Duke of Cambridge said he's "absolutely thrilled" about his brother's new addition and is "looking forward to seeing them in the next few days when things have quietened down," according to Hannah Furness, royal correspondent for The Telegraph.

View this post on Instagram

"We're absolutely thrilled - welcome to the Sleep Deprivation Society!" — The Duke of Cambridge on his and The Duchess's delight at the birth of The Duke and Duchess of Sussex's son

A post shared by Kensington Palace (@kensingtonroyal) on May 7, 2019 at 7:37am PDT

William then continued giving a tip or two about parenting in an epic dad joke, "I'm very pleased and glad to welcome my own brother into the sleep deprivation society that is parenting’’ he added.

"I wish him all the best. I hope in the next few days they can settle down and enjoy having a newborn in the family and all the sort of joys that come with that as well’’ Prince William adds.

Prince Charles, who is headed to Germany with Duchess Camilla, "We couldn’t be more delighted at the news and we’re looking forward to meeting the baby when we return," according to Sky News.