I want to be sure you only have the one male and female on the cage now? It would be best to move the extra make to another room where the male & female can’t see him. Having the three of them together created confusion for them. It’s never a good idea to have an odd number of birds together, because they want to pair off, and once they do, the odd bird gets picked on. Your male and female never had a chance to properly bond because of having all three bird together. While she did lay eggs, she and the male are not getting along well enough to take care of the eggs together. He may have some attachment to the other male. But some males in a pair do behave this way, becoming aggressive and keeping the hen from going into the nest. If he is attacking her to the point of pulling out her feathers or drawing blood, then you have to separate them. He can end up killing her. What you can try is to remove one of them, let the other sit on the eggs during the day, and then swap them and let the other bird sit at night. Try this for a few days, and then try letting them both be together again. If they still fight, then all you can do is keep swapping them morning and night. After this clutch, you need to take the nest box down and rest the birds for 6 months. Either remove it when the eggs fail to hatch, or if they hatch chicks, remove it as soon as the chicks have left the box. Once the chicks are weaned, remove them and rest the pair for 6 months, ideally keeping them together. Do not give them a box again after 6 months unless they have started to get along and are not fighting anymore. If they keep fighting, you might try the other male with her. Do not put all three together again, and do not let the chicks be in the same cage as either parent. Never allow related birds to breed. Hopefully the pair will work things out, but not all birds will get along well enough to breed.
Thank you for asking Lafeber,