Michael Phelps is set to become a father of two.
The 23-time Olympic swimming champion and his wife, Nicole, announced the news on Instagram with the help of their 15-month-old son, Boomer.
Phelps shared a picture of Nicole holding a smiling Boomer and wrote in the caption: ''Number 2 on the way!!!! So excited!! Wonder if it's a boy or a girl??'' Boomer has a big following on his own Instagram account, where another picture showed the smiling boy alongside a positive pregnancy test.
Boomer was born in May 2016, a month before Phelps and the former Miss California USA got married.