Why are my lovebirds eating their own eggs?

My lovebirds are eating their own eggs but i don't know why? I think maybe its crushed,because today my female bird had her egg on her belly because the egg was broken.This happened ever since my new male lovebird started mating with our female bird then the first egg it was on top of the birdhouse and i think they ate all the eggs but i gave them food but their still eating their eggs or maybe it's just crushed,please let me know why.