The Fun frontman thinks it would be "fun" to have a baby with his "Girls" actress girlfriend - who he has been dating since 2012 - but suggested his partner isn't ready just yet, reported Femalefirst.
"I think about it a lot and it seems like fun. We talk about it all the time... But Lena has her own thoughts on that," Antonoff said.
The 32-year-old musician believes the key to their relationship is "trust" and giving one another the space they need to work.
"There's a lot of trust there. When it comes to people's art, you need to give them the space they need.