As the law stands currently cheating partners will not count towards divorce proceedings for a same sex married couple, because the law only sees sex as a legal action between two members of the opposite sex, when concerning marriage.
“The same dilemma exists in relation to the consummation of marriages. At present, marriages can be annulled on the grounds which include the parties not consummating their union. The government intends to exclude same sex couples from annulment on the grounds of non consummation”, writes Duggins
“Efforts to bring marriage equality to same sex couples have raised an interesting legal dilemma for legislators when reviewing the current law surrounding divorce. At present,
a married person can rely on their spouse’s adultery to evidence the irretrievable breakdown of the marriage. Although not defined by statute, adultery has been defined
by case law as sexual intercourse between persons of the opposite sex.”