"Did you ever wind up reading the Jessica Simpson book?" Cohen asked Lachey on Monday's show.
"You'll be shocked to hear that I have not. Nor will I ever read that book," the 98 Degrees singer, 47, replied.
"Did you have someone pull you and say, 'Listen here are the five things you need to know that are in this book'" Cohen continued. "Like here are the five things you are going to be really annoyed by or someone to give you the low down."
"No," Lachey said. "Here's the thing, right? I obviously knew the book was coming out, but I lived the book. You know what I mean. I know what the truth is so I don't need to read it or read someone's version of it in a story. I know it, I lived it. No, I never read it."
"And now there is going to be a fictionalized drama based on her life," Cohen added, referring to Simpson's upcoming scripted series for Amazon. "I mean you have to be saying, 'Well how is this going to go for me.' And who is going to play me?"
"Nah, you know what man, I am thrilled to be where I am in life. That was 20 years ago. It's honestly the last thing on my mind these days except when someone brings it up," Lachey said. "I understand why people want to ask but it's just so not a part of my life anymore that it's not even on my radar. She is doing her thing and I am doing mine and that's the way it should be."
Lachey and Simpson have both happily moved on.
Lachey and Vanessa Minnillo tied the knot in 2011 and share three children: Camden, 9, Brooklyn, 6, and Phoenix, 4. Simpson and husband Eric Johnson, who wed in 2014, also share three children: Maxwell, 9, Ace, 8, and Birdie, 2.
Jessica Simpson is completely "unrecognizable" in photo taken before she got sober in 2017: