Rhodri also said that he had only found out about his brother's betrayal the day it was revealed by The Sun newspaper, even though he had "an inkling a couple years before" only to be convinced otherwise by his mother.
"I found out on the day the papers put it out, her mum came to my house at six in the morning."
"It was a night of a United party and I was supposed to be meeting her and I was ringing her and she wasn't answering," he added about his suspicions that something was going on. "I thought 'I'll know where she'll be'. I went to the party and she was in there."
Both Ryan and Natasha attempted to reconcile with Rhodri, but he insisted the apology "was not real, it was all fake".
"Six months down the line he said he's going to do this, do that and then nothing has happened," Rhodri said. "He expects me just to forget it and act like things are normal but no, I went to the papers and from that day they never spoke to me."
Rhodri said he has been hurt by his mother siding with Ryan, saying "it's like I've done the affair".
"I've got three children, one who's five who she's never met and one who's 13 who she hasn't seen for seven or eight years, what have they done? They live a mile away.
"Ryan's got a son who's exactly the same age, these people should be mixing with each other and looking out for each other but instead, they don't even know each other, that's the sad thing.
"I don't speak to any of my family, none of them speak to me, they all speak to Ryan and they all live in Wales and go to Wales games and have nice food and nice hospitality.
"It's what they like, I don't really get off on stuff like that, I never have … It's all pretentious crap."
The affair was first revealed in June 2011 by when Natasha admitted to an eight-year affair with the former star player in an interview with The Sun, and claimed she had aborted Ryan's baby just weeks before she got married to Rhodri in Las Vegas.
Natasha decided to go public after Ryan's controversial attempt to silence Big Brother star Imogen Thomas about their six-month affair.
"He was a young, humble, hardworking guy, still a hardworking guy, but now a cocky, arrogant and thinks he can get away with anything type person," Rhodri said of his brother.