Desdemona is clear that she will be loyal to her husband as soon as their marriage is public. She explains her ‘divided duty’ as a daughter and a wife, but as tradition dictates, her allegiance will pass to her husband-
I am hitherto your daughter. But here's my husband,
And so much duty as my mother show'd
To you, preferring you before her father,
So much I challenge that I may profess
Due to the Moor, my lord.
When discussing with Emilia their relationships with their respective husbands, Desdemona is adamant that she would remain loyal to her husband, and would not betray him
for the whole world.
It is Desdemona’s final words which clearly assert her loyalty to Othello. Despite being told she is on her death bed, Desdemona refuses to confess to a liaison with Cassio which did not happen-
I never did
Offend you in my life; never loved Cassio
But with such general warranty of heaven
As I might love.
Her final act of loyalty to her husband is to condemn her self to purgatory as she lies on her death bed to protect Othello. She refuses to identify him as her murderer and blames herself for her own death-
O, who hath done this deed?
Nobody; I myself. Farewell;
Commend me to my kind lord. O, farewell!
Desdemona idolizes her husband, Othello. For Desdemona, Othello represents an exciting, adventurous future and a tacit rejection of the Venetian society in which she was raised. Part of Othello's attraction is his identity as a warrior—he is a dangerous man who has survived many adventures on the battlefield. Desdemona is attracted by these stories but also a bit frightened by her husband's temper, which is why she misleads him about the handkerchief, an error that Iago exploits to destroy almost everyone in the play. Yet her loyalty to her husband is almost comically naive. Take her conversation with Emilia in Act 4, scene 3, in which Desdemona asks her if she thinks there are women who cheat on their husbands. Emilia's answer, in which she not only affirms that there are such women but argues that their behavior is justified by the treatment they receive from their husbands, shocks Desdemona, who can only say that she hopes to learn from such women in order to avoid their conduct. Desdemona remains true to Othello, even to the point of her death at his hands, when she tells Emilia with her last words (Act 5, scene 2) that she is responsible for her own death!