One by One - Season 3 Episode 10 Coming to Terms
Overview: On the eve of Ethe's wedding to Teddy, Donald is called to Madrid Zoo, where Shao-Shao the Giant Panda is showing signs of going into labour. A tearful Ethel asks Paddy to take his place in giving her away. After the baby panda is born he flies home to witness the marriage, to the delight of Ethel.