The Rivals

When Opie develops a crush on a classmate named Karen, he's too shy to ask her out. Seeing the bind that he's in, both Thelma Lou and Barney go about giving him advice on how to work up the courage to ask her to the movies. Barney's advice works almost too well, and as a result, Opie's affections move from Karen to Thelma Lou. As a result, Thelma Lou, Barney, and Andy work together to find a way to convince Opie to ask Karen out.