The love-triangle comprized of Duke Orsino, Countess Olivia, and Viola is suddenly and hastily sorted out at the end of the play by the arrival of Sebastian, who squares the triangle and marries Olivia. Olivia does not know Sebastian and only wants to marry him because she mistakes him for Cesario, the alias Viola has been using. Viola is in an embarrassing position for a number of reasons. She has deceived both Orsino and Olivia by pretending to be male. Although the audience understands that she has, aside from this one deception, been scrupulously honest, neither her future husband, not the woman who fell in love with her, believing her to be male, knows this. Viola presumably feels that she is in a very ambiguous position, and thinks that the less she says, the better.
The audience may well wonder why Viola is attracted to the melancholy Orsino. Viola, however, after silently pining for Orsino while unable to reveal her feelings, may be more inclined to wonder about Orsino's sudden decision to marry her. Has he done so simply because Olivia is no longer available? Given this further reason for uncertainty, it is difficult to imagine what Viola could say at this point if she were to break her silence.