Lily and Robin met each other in the segundo episode, purple giraffe, after Lily recognizes Robin from her news show and also Ted. Robin and Lily seem to be really good girl friends, hanging out and shopping together. In 'The Wedding' Robin confesses about her feelings for Ted to Lily who tells her to tell Ted about it. Lily says in Arrivederci Fiero that they became best friends por keeping a secret together. When Lily returns from San Francisco Robin is the only one who supports her and even helps her to find an apartment. Robin was also the maid of honor in Lily's and Marshall's wedding which further proves their friendship. Lily is supportive in all of Robin's relationships that she had known from Derek to Don. Lily often insinuates that she has a girl crush on Robin.