Under what conditions would Desdemona cheat on Othello?

In Act 4 of Shakespeare's Othello,
Emilia declares that she would not cheat on her husband for a trinket, but she would for
the whole world:

It is a great
price

For a small
vice.

Yet, Desdemona declares
that she would not cheat on her husband even for the whole world.  Earlier in the play,
Desdemona declared that even if Othello treated her badly, she would still love
him:

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Unkindness may do
much.

And his unkindness may defeat my
life

But never taint my
love.

And, she declared
that

I cannot
say "whore,"

It doth abhor me now I speak the
word.

To do the act that might the addition
earn

Not the world's mass of vanity could make
me.

Desdemona's love for
Othello is pure, constant, and unconditional.  She would never cheat on Othello.  Unlike
Emilia, Desdemona's love is absolute; no price or prize could tempt her to commit
adultery; no unkind act on Othello's part could drive her to another man.   Under no
circumstances would Desdemona cheat on Othello.