Ask him what his plan is?? Is it to live at his parents forever and never have a job?? Or maybe he has an idea of what he wants to do. If he does tell him to hurry up and get on with it if he wants a baby, LOL.
If he has no idea maybe you could both come up with some options together. Maybe having a bigger picture of where he eventually wants to be will motivate him instead of concentrating on just getting any old job. Might feel like he's working towards something if he has a goal if that makes sense?

It is not reasonable for him to expect to live at his parents for much longer with one baby let alone two!! Give him a kick up the bum.