The pop star is head over heels for his dancer partner, and they recently moved in together in London.
But Liam, who is still just 18, reportedly wants to take the leap and get wed after talking about commitment with the rest of the band at their pal Marvin Humes' wedding to Rochelle Wiseman last month.
“The boys were joking he would be next at Marv and Rochelle’s wedding - and he didn’t deny it."
And he's so smitten with Danielle, he wants to start a family with her.
The insider adds: “He’s said all along he wants to be a young dad. He reckons at 25 he’ll be on nappy changing duty.”
Liam admitted earlier this year that he is under the thumb when it comes to his relationship - revealing he has to tidy up after himself at home or he gets in trouble.
> IN PICS: ONE DIRECTION'S ROAD TO WORLD DOMINATION