The Fall Out Boy and his longtime girlfriend, Meagan Camper, are expecting a daughter this year.
Wentz made the announcement on Monday night, sharing a sweet photo of his two sons, 9-year-old Bronx Mowgli and 3-year-old Saint Lazslo, smiling as they sit on steps outside. In the pic, Saint is holding up a wrapped pink box.
"Happy New Year! We’re kicking the year off with news of the best gift yet: 👧🏻 coming to our family in 2018... love Pete, Meagan, Bronx and Saint," Wentz wrote.