Cosmo's teen photos from "School's Out!: The Musical" and "Wishy Washy" can also be seen in the beginning room of the board game on the wall.
There is a discontinuity from this episode and "Schools Out!: The Musical". In this episode, it is said that Cosmo ran Wanda over. In Schools Out, it is shown that Cosmo and Wanda met in a diner that Cosmo was working at. Since the "sappy love song" was a trick, it is possible that it is not true. However, there has to be some truth to this because on the wall in this episode, there is a picture of Cosmo in his waiter outfit.
The same error happens in "Odd Ball" when Cosmo told Timmy he stuck with Wanda because he hit her with a dart, and Wanda still had the scar to prove it. However this event may have happened after they fell in love and Cosmo may have had other crushes, and that is how he picks Wanda.
There is also a discontinuity with "Fairy Idol". In Fairy Idol, it is said that fairies are fast healers. However in this episode, it said that Wanda needed surgery. A similar error is derived from Big Daddy because he has a scar and the only way he could get a scar is if he didn't heal quickly.