Is a person held accountable for his lust, such as lusting after his sister despite his intense loathing for that?

Incestuous desire is a deviation from human nature (fitra) and is considered a sin if it is brought about by the person or if it settles in their mind and they do not repel it. The Prophet, peace and blessings be upon him, called it the zina (adultery/fornication) of the eyes, ears, tongue, hands, feet, and heart. However, if the desire occurs without the person causing it and it is repelled, then the person is not held accountable for it. Nevertheless, one must be wary of Satan's enticement and not be complacent with satanic thoughts, as they are the seeds of Satan that grow until they bear evil deeds.