Lilly's high school friend, has the same name as the character Alyson Hannigan played in the American Pie series
The movie is mentioned in the end credits "Bro Code #41".
Robin says a friend from Canada is visiting, and Barney asks if it's someone she went to Degrassi with.
When Robin tells the group about her summer of love, Barney responds with "tell me more, tell me more, like did he have a car?"
Panda mentions that Dawson got a depression after Batman stole his girlfriend and a stillimage from "Sandcastles in the sand" is shown
Robin's second video "Sandcastles in the Sand" is shown.