The singer-songwriter infamously referred to Simpson as "sexual napalm" in a 2010 interview with Playboy magazine.
"Yeah, that girl is like crack cocaine to me. Sexually it was crazy," he told the mag. "That's all I'll say. It was like napalm, sexual napalm."
But when it comes to his romance with Perry, Mayer remained fairly schtum.
"It was a private relationship during, and it's a private relationship still," he said about the Part of Me singer.
He added, "I can understand asking the question based on some previous answers I have given, but I have finally learned how to put the wall between one thing and the other. I've been much happier since then.
"I'm on the same journey as everyone else. Coupling is a tricky thing. It's a tricky thing."
Added DeGeneres: "It is hard and you're both in the business and you're both working all the time. I just want you to be happy. That's all."
"I want everyone to be happy," replied Mayer. "And you're happy."
"I'm happy," chirped DeGeneres.
Mayer and Perry first stepped out as a couple in early August. Just a few weeks later, the romance was rumoured to have hit the skids. But they patched things up, only to split again last month.
"It's sad," a friend of the couple told Us Weekly, while noting that the split might not be a permanent thing. "It's not over until it's over. You have to see how things play out."
Chimed another source: "She's leaving the window open. They have both been so focused on work."
During his confab with DeGeneres, Mayer, who is prepping for his first tour in three years, also spoke about his recent throat injury that resulted in two surgeries on his vocal cords.
"Half of it [was acid reflux], half of it is overuse and singing and singing and singing. The other stuff is you know, what you put into your body. And, I'm getting to that age now your body doesn't just shake everything off, and it didn't help that I really loved, loved, loved scotch. It's just like applying poison to your body," he noted.
"It's like applying a shellac of poison. It's just delicious, wonderful poison. That makes you not care how late you're out till or where you're going.
"I had to really say, 'I like singing and writing more than I like delicious scotch.' So I had to really dial it down. And I'm a little more boring now."
"Ultimately, it makes you probably a lot more interesting," DeGeneres added.
Watch a portion of the interview below:
NOTABLE NUGGETS
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* "I do think it's important but we have no plans" - Kate Hudson says she and British beau Matthew Bellamy will get married - eventually.
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* Clark Gable's son, John Clark Gable, arrested on suspicion of DUI.
* Tom Hanks is going to be a grandpa again: Son Colin Hanks and his wife Samantha Bryant are expecting their second child, rep confirms.
*Chris Brown compares himself to Justin Bieber (aka "Baby Elvis"), says they both get bad raps in the press.
* Beyonce calls herself a "modern-day feminist".
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