This one comes from episode 16 of season 12 called “Bye, Bye, Nerdie”. Arguably this is after the golden age of the show so it’s not entirely a fan favourite. The story line goes that Lisa gets picked on by a new kid at school, and through investigation finds out the new kid picks on nerds due to their smell. She develops a spray that masks this smell and helps out all of nerdkind. At one point a kid on the busy ironically comments on the new kids appearance saying she’ll never fit in. This kid is wearing a Frankie says relax shirt, which was a thing in the 80s from the song.

Here’s the link to the product as a pin, but you can view the design on multiple items if you’re interested.