Baby budgies are adorable for sure, so I understand why you want to breed your budgies!
I also want things sometimes, but I have to consider the consequences.
Breeding budgies is not
as simple as having two birds and giving them a nestbox. They need a special diet and correct temperament to breed, among many other things.
You must be able to make good decisions that will ensure your budgies are healthy and safe, even if it means putting off breeding until you have a better grasp on the subject.
The advice you've been given above is absolutely correct. It's imperative that you separate your budgies--your male is not "sexually charged", he's aggressive, and could hurt your girl
Since I know
you don't want anything bad to happen to your budgies, I hope you will follow this advice!
I look forward to hearing how they're doing soon