Sebastian recently admitted he had been involved with Goodrem shortly after he shot to fame as the winner of reality Tv show Australian Idol in 2003, and called her his "hall pass".
The comment sparked speculation he had cheated on his childhood sweetheart Jules, who he married in 2008, and Sebastian has now revealed the false reports prompted an outraged text message from Goodrem.
He has now spoken out to clarify the situation, insisting he was on a year-long break from his relationship with Jules when he became involved with Goodrem, telling the Sydney Daily Telegraph, "Suddenly, I was like a cheating scoundrel with Delta texting me: 'Guy, what the hell?'"
He adds of his brief romance with Goodrem, "It was at a time when I was very new in the industry. Delta was doing things in music and she was a great friend. I wouldn't even call it a relationship."
Sebastian and Jules are now parents to two sons.