No one told parrotlets they are the tiniest of all parrots. They can have huge attitudes and egos, they will have no issue starting a fight with your budgies if decide your budgie needs to move. The little ones I worked with chased my bare eye cockatoo.... never exoected it, so was very careful after that. Never let them have another chance to pick a fight. You might find a parrotlet who doesn't mind a budgie on their playstand, just be prepared to have separate areas.