Pete Wentz is to become a father for the third time.

The Fall Out Boy musician and his girlfriend Meagan Camper already have three-year-old son Saint Lazlo together, but in a sweet Instagram post shared to ring in the new year on Monday (01.01.18), Pete - who also has nine-year-old Bronx Mowgli with his ex-wife Ashlee Simpson - confirmed the pair are expecting their second child together.

Posting a picture of his two sons holding a pink present, the 38-year-old bassist wrote: ''Happy New Year! We're kicking the year off with news of the best gift yet: [baby girl emoji] coming to our family in 2018... love Pete, Meagan, Bronx and Saint. (sic)''

Previously, the 'Centuries' hitmaker likened being a father to taking ''happy pills'', as he finds his young tots' laugh to be ''the funniest thing on the planet''.

He said: ''I have two kids, and if I hang out with them it's pretty much like taking happy pills. When you hear a one-year-old laugh, it's pretty much the funniest thing on the planet. It changes my mood ...

''My highs, my happiness are really high and my lows are very low and I'm not able to regulate between the two. Through actual therapy and having kids it's way more under control and something I can see when I'm on the roller coaster and control it more.''

And Pete also claimed he'd like to make sure the world was a happier place for his brood as they grow up.

He said: ''I think that I look out at the world sometimes, especially having kids, and all I see is negativity and hate that's so divisive.

''It bums me out and I know that people have a hard time - I've had a hard time - and one of the things you should know if that you can make it out of the other side and be stronger because of that. That's why I think it's important.''