On Kimi's birthday (she's 2 now, isn't she?), Stu plans to take the kids to a family-friendly place called "The Happy Castle", where Kimi will have her party. But, for some reason, they arrived instead at a gothic / punk nightclub, where Taffy is playing with her band. Thinking that the party is here, they try to find the birthday cake, which, by the time everyone gotten to it, was already melted. (thetvdb.com)