A.J. McLean is expecting a baby girl.
The 38-year-old singer and his wife Rochelle - who already have three-year-old Ava - will welcome their second daughter into the world in June 2017.
The Backstreet Boys star is thrilled that he is having another girl as his bandmates all have boys.
He said: "A lot of girls in the house!
"I will take that over testosterone running around the house, to be honest with you.
"All my boys have boys, so it's nice to have girls. Girl power all the way!"
The 'Everybody' hitmaker also shared how his first child has been pretending she is pregnant too and can't wait for the arrival of her little sister.
Speaking to Entertainment Tonight, he said: "She has her own little baby that she's been tucking under her shirt like she's pregnant! She's like, swaddling her babies now ... She loves it, she's so sweet and she's just an awesome kid."
The hunky pop star also revealed that Rochelle is due to have the baby around the same time as Backstreet Boys' Las Vegas Residency, which kicks off in March until June, "literally just shy of a week after" their 'Larger Than Life' shows at Planet Hollywood's The Axis Theater.
A.J. hopes he doesn't get a phone call to say Rochelle has gone into labour mid-way through a performance.
He said: "Hopefully I'm not in the middle of the show and all like, 'I have to go!'"
A.J. first announced he was to be a father for a second time last month when he posted a photo of four different sizes of the same Air Jordan trainers.
Alongside the picture on Instagram, he wrote: "So the Mclean family will be expecting a new addition to the family next spring!! #laborday! Ha get it "labor" day! I'm a goof! #avaisgonnabeabigsister #baby2! Keep u all posted!! We're so excited. (sic)."
The 'I Want It That Way' hitmaker has no misconceptions about raising a second child as he insisted that while it might be "easier" the second time around, it'll still be a "brand new" process.
He previously said: "Whatever our next child is, boy or girl, you would think that 'Oh I did it once, I've got it.' No. It's hard. It'll make it easier, but it's still going to be a brand new learning process."