It's an odd quirk of the law in this day and age that infidelity with a person of the same sex is not regarded as adultery for the purposes of establishing grounds for divorce. Although, in practice, those who find themselves in this situation can rely on their spouse's unreasonable behaviour to establish grounds for divorce instead, the fact remains that the law as it stands seems pretty clearly discriminatory.

There is a strong case for changing the legal definition of adultery, and an even better argument for switching to a genuinely 'no fault' divorce system in which there is no need to establish grounds for divorce in the first place.