One Direction singer Niall Horan is to be an uncle after his older brother Greg Horan announced he is expecting a child with new wife.Niall Horan is to become an uncle.The One Direction singer learned the news while acting as best man at his brother's wedding on Wednesday.Niall, 19, will be expecting to take on his novel familial duties as uncle later this year when the little girl or boy is born to older newlywed sibling Greg Horan."It's Niall's first niece or nephew so he's delighted," Greg gushed to British newspaper The Sun.Greg tied the knot to beauty therapist Denise Kelly near their home in Ireland. The UK's X Factor 2010 alumni Niall reportedly began their special day by singing The Day I Crashed The Wedding while driving family members to church in the country's Westmeath area.The friendly teenager even stopped to sign autographs for fans before walking into the church by his relatives' side.Niall and Greg's mother Maura revealed there was a big buzz ahead of the ceremony."God bless us sure we are all here now and I don't think the nerves are too bad," she pointed out. "Everyone will be here and there was fun getting ready - it's a great occasion."Apparently some admirers of Niall and his fellow group members Louis Tomlinson, Liam Payne, Zayn Malik and Harry Styles, managed to bypass security to jump into Niall's unlocked Range Rover car. But no one was hurt and the occasion remained joyous.