Near the end of Act I, scene i, Benvolio asks Romeo what's bothering him and Romeo comes out with it. He tells Benvolio how bummed he is that the girl he likes has sworn to live chaste. Benvolio listens, and in the end offers advice:

By giving liberty unto thine eyes;
Examine other beauties.

Benvolio said this in response to Romeo's question about how to get over Rosaline. His advice is advice a good friend would give: there are other fish in the sea. This also shows that Romeo trusts Benvolio enough to divulge tough information. The question or significance that phenomenon is that later in the story, Benvolio should be someone Romeo reveals his deepest secret to, but he doesn't.