Dexter told Delilah that the feeder opening is just not built for two to eat from at the same time and she must wait for her turn. Delilah had hoped that they could alternate bites, but Dexter impatiently told her that he has seniority and gets to eat first.
Delilah was concerned that Dexter was going to eat the lion's share and not leave any for her, so she stood guard on top of the feeder imploring him to save some for her.
Dexter finally told her that he was full and she could eat now. Delilah was relieved to see there was some left afterall.