The thing with the bathing suit is an actual thing that happened to Michael Showalter at summer camp. He had to go the bathroom and when he couldn't hold it in he got rid of the evidence in the woods. When someone found the shorts he claimed they weren't his. They showed him the name tag on the shorts which had his name so he suggested that someone stole his shorts and took a dump in them and then left them in the woods.
Lindsay reveals her age to be 24, which is roughly the age at which Elizabeth Banks filmed the original movie. This makes Banks one of the few actors playing their actual age in the movie.
When confronted at lunch about his soiled swim trunks found in the woods, Kevin says someone stole them, soiled them, and put them in the woods. Christopher Meloni's character responds by saying, "That is the only logical explanation." In David Wain's previous film, They Came Together (2014), Meloni's character uses the same excuse for a similar incident and follows up his story with the very same line.
Marisa Ryan, who portrays a character who rapidly goes through puberty in this episode, previously appeared in Puberty: The Movie (2007). (This movie also starred other actors from this series, including David Wain, H. Jon Benjamin, and Joe Lo Truglio.)
When Kevin's crap-filled bathing suit is found by Drew, Kevin tries to explain it as someone stole his suit and crapped in it. This is almost identical to a scene in David Wain (co-creator)'s previous film, They Came Together (2014).