Pete Wentz still believes in marriage.

The Fall Out Boy bassist, who split from Ashlee Simpson in 2011 after three years of marriage, is open to tying the knot with his girlfriend, Meagan Camper, for the sake of their five-month-old son, Saint, but is in no rush to walk down the aisle again.

The 35-year-old rocker, who also has six-year-old son Bronx with Ashlee, said: ''When you're really committed to somebody, you know that you're going to be with them, whether a ring changes that or not. I think it's important to the kids. I do still believe in marriage. My parents are married. My sister is married. I'm a man in love!''

Meanwhile, Pete admits he initially felt like his ex-wife, who is currently expecting a child with husband Evan Ross, ''bailed'' on him while he was battling depression after his band went on hiatus in 2010, but insists they are now friends.

He told Howard Stern on his SiriusXM radio show: ''I would be an idiot to think that I didn't contribute to the unravelling of it. Of course, at first, I'm like, 'This sucks! You bailed on me!' But you get perspective. We have a kid together. Our kid is awesome. He's great.

''We've actually figured out how to parent that way in a really good, healthy way. And we can be friends.''

Pete also thinks he and Ashlee weren't mature enough to be together at the time.

He said: ''I think there's an important thing where you know how to fight, because you can fight with somebody and it's not the end of everything. But if you don't know how to have those arguments, then they become nuclear.''