Liam Payne's ex congratulates him on baby with girlfriend Cheryl

Liam Payne's ex Sophia Smith has congratulated him on welcoming a baby with girlfriend Cheryl.

The One Direction singer dated fashion student Sophia for two years until they split in October, 2015. He quickly moved on from the end of the relationship and began dating former X Factor judge Cheryl in early 2016.

The couple shocked fans when the 33-year-old Girls Aloud star fell pregnant just a few months into their new romance, and the pair welcomed a baby boy in March (17).

Sophia has no bad feelings towards her famous ex, and told British newspaper The Sun she had even messaged her 23-year-old ex to congratulate him on the birth of his first child.

"I messaged to congratulate him,” she said at Coachella Festival’s Revolve party. "We’re all good. I’m happy for him."

Sophia has come a long way since she first commented on Liam and Cheryl's relationship last year (16), calling their budding romance weird.

"It's so weird. I knew about them a little bit ago, but who thought it would actually come out?" she told Now magazine.

When asked if she felt okay about the new couple, Sophia added: "Yeah.... I'm okay. I'm all good."

Cheryl and Liam confirmed the arrival of their bundle of joy on 25 March (17), by sharing a picture of him cradling the newborn son against his chest on Instagram on the eve of Mothering Sunday in the U.K.

Liam has since thanked fans for their well wishes on Twitter and he later joked about how many times his son's nappy has needed to be changed.

“When the fourth nappy happens in 5 minutes," he wrote next to a GIF image of David Schwimmer's character Ross Geller from TV show Friends yelling "NO! No, no!"