When Robbie's girlfriend's father calls from out of town and asks him to deliver a birthday cake to her, he thinks there might be a fortune in performing this birthday service and immediately goes into the cake business.

The day before her wedding Katie Miller feels she faces complete disaster. When Robbie tries to console her, she flares up at him and after a short argument, the pair declare the wedding is off. Of course, Grandma Collins thinks otherwise.

As the triplets come home from the hospital their names are announced by the happy parents: Robbie Jr, Charley and Steve II. Their father Robbie finds that he is totally unprepared for all of the attention that the infants attract.