 Barney just can t seem to loosen up on his dates with Thelma Lou; he s ill at ease and can t put two words together unless he s talking shop. He has no trouble telling Andy how he feels about Thelma Lou - she s the cats - but he just can t tell her. After Andy tells Thelma Lou how Barney feels, she decides to make him jealous and tells him that Andy came calling on her. Barney s ready to fight; he won t listen to Andy s explanation and makes a play for Ellie. When Ellie tells Andy what happened he wishes he d never got involved but Ellie figures out how the two of them can set the other two straight and things work out.