Post Malone and his mystery girlfriend are expecting a baby.

The 26-year-old rap star claimed that he is the "happiest" he has ever been as he announced on Tuesday that his long term girlfriend – whom he has never identified publicly – is pregnant.

He told TMZ: "I'm excited for this next chapter in my life, I'm the happiest I've ever been, and for since I could remember I was sad! Time to take care of my body and my family and friends, and spread as much love as we can every day."

The outlet went on to claim that sources close to the 'Circles' hitmaker – whose real name is Austin Richard Post -said he had celebrated the happy news with a private party for friends and family over the weekend and that the two have been "privately building" their relationship since getting together in January 2021.

An insider said: "They celebrated the baby-to-be with a private party for friends and family in Southern California over the weekend but [his girlfriend] is not someone who has spent any time in the spotlight and two have been happy privately building their relationship, which will soon turn into a family!"

News of the pregnancy comes just days after the 'Better Now' rapper announced that he will release his fourth album 'Twelve Carat Toothache' in June.

In a simple social media announcement, Post shared an anatomical heart emoji on Instagram and wrote: "Twelve Carat Toothache. June 3rd."

The star dropped lead single 'One Right Now' – a collaboration with The Weeknd – almost six months ago, and his manager Dre London previously claimed that the album would be released in May.