Does marital infidelity count as a divorce if the husband had informed his wife upon their engagement of his intention to steer clear of such sins, and does this constitute a breach of the marriage contract?

The husband's committing indecency does not result in the annulment of the marriage, nor does the husband's informing his wife before marriage that he avoids indecencies affect the sanctity of the marital bond. Whoever falls into indecency must repent to Allah by abandoning the sin, feeling remorse, and resolving not to return to it, while concealing oneself and not publicizing the sin. It is important to note that labeling a husband's illicit relationships as "betrayal of the wife" might suggest that their condemnation stems solely from being a betrayal of the wife, which is a concept contrary to Islamic law.