In fact it seems both Liam and Miley are ripe for reproduction, with a friend of the couple's revealing they want to start a family ASAP.
"They are both mature and ready for this," the friend told Us Weekly, adding, "Miley is 19 going on 40."
The duo have had a bit of parenting practice looking after the five dogs they own together, but Liam is said to have become extra clucky since the birth of brother Chris's daughter India in May this year.
"Miley and Liam really want to have a baby quickly," said the friend.
Let's hope they realise having a kid is a little different to looking after a barking brood of canines. Those all-nighters could come as a bit of a shock!