Kian married his longtime love Jodi Albert at a lavish ceremony in Barbados last May, just two months before his father's tragic passing.
"I probably cried just as much at Nicky's dad's funeral as I did at my own dad's," he told the Herald.
"It wasn't because I was sitting there thinking my dad is gone as well, it's just because I know what it feels like. I know the pain. It was just a very sad time, you know.
"I knew what he would have to go through, what his mother would have to go through.
"When my dad passed, I just wished that no-one else in Westlife had to go through that pain.
"My dad was very sick with cancer for a long time and he suffered a lot at the end, so you know in a sense for Nicky's dad to have passed so quickly after my own, it was very strange and very difficult.
"It was just very fresh and I just wish it wasn't so close.
"All of our fathers are of similar age. Nikki Sr was too young to die. My dad was too young to die. It shouldn't have happened. We got the rough end of the stick," he added.
The star, who stepped out alongside his bandmates Nicky, Mark Feehily and Shane Filan last night to perform at the Cheerios Childline Concert at the O2, says that his pal Nicky has been remarkably brave and says he was right to throw himself back into his work.
"We all took the week off for Nicky and he's been very strong," he explained. "Both of our fathers would absolutely kick us asunder if they saw us at home sitting on our ass.
"We've an album coming out in three weeks and both of our dads' lived for Westlife so we're doing it for them really.
"We're not going to get anywhere by sitting at home moping," he added.