Rocker Pete Wentz is in no rush to make his pregnant girlfriend Meagan Camper his wife, because they already have a lifelong bond through their children.

The Fall Out Boy star has already walked down the aisle once, with his now ex-wife, singer/actress Ashlee Simpson, and after finding love again with Meagan, he's learned not all romances have to lead to marriage - although he's not opposed to the idea.

"It would be nice to celebrate something with our friends and our family," he tells People magazine, "but the relationship and commitment and responsibility we have to each other and to our kids is so much bigger - it's a lifetime thing. So I think there's not a rush."

"I have a cool partner, I have a cool job, and I feel very lucky," Pete adds.

The couple already shares three-year-old son Saint, and the bassist rang in 2018 by revealing their family would soon be expanding with the addition of a little girl.

Pete, who also has nine-year-old boy Bronx with Ashlee, admits he cannot wait to meet his daughter.

"We have a lot of testosterone in our house," smiles the 38-year-old. "I see my friends who have daughters, and it seems like a whole different kind of love that they have for each other, so I look forward to that being a completely new journey. Hopefully it'll bring some balance to our home!"

Pete and Ashlee were married from 2008 until their divorce was finalised in late 2011, just a few months after the rocker started dating Meagan.

Ashlee has also moved on - she is also mother to two-year-old daughter Jagger, with her husband Evan Ross.