If Hollywood's taught us anything, it's that young love often leads to heartbreak. And Fall Out Boy bassist Pete Wentz experienced just that when his marriage to Ashlee Simpson crumbled in 2011.

"I thought it was forever," the musician told Howard Stern on his Sirius XM radio show. "My parents have been married, I think, 35 years. I don't really know. Forty years, this year, maybe?…At the same time, we were both very young."

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The duo with Bronx in 2010.

Pete was 28 and Ashlee was 23 when the pair tied the knot in 2008. Ashlee was three months pregnant at the time with their son Bronx.

But it was Fall Out Boy's hiatus in 2010 that really caused a strain on the marriage. "Here's what it really was. At 31, we'd had all these great years as a band, and then we took time off, and I basically became Mr. Mom," he said.

"I had the beard, the flannel shirt. I didn't know what my identity was. That factored in. When your identity is what you do, it's hard when you stop doing it."

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Although he at first felt like the actress had "bailed" on him when she filed for divorce in 2011, Pete says they ultimately had an amicable split. "We have a kid together. Our kid is awesome. He's great."

Since their separation, Pete has welcomed a son with girlfriend Meagan Camper and Ashlee is expecting a child with husband Evan Ross. The Grammy nominee explained why he had yet to propose to Meagan.

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Pete with current girlfriend Meagan.

"To me, the right way is when we have time to plan it. I didn't really want to do it in the public eye this time. I didn't really want to do it in magazines," he shared. "We're just doing it on our own a little bit."