‘Real’ love can be seen to be a rather slippery commodity in the play. Orsino's final words may be evidence of this.

Orsino says to Olivia, But when in other   you are seen, / Orsino's mistress, and his (fancy's) queen. (V.1.364–5)

Ask yourself: Has Orsino fallen in love with an idea again, or is his love for Viola genuine?