Do you feel it will harm your position if you disclose this? Just curious to hear the reasoning behind the question.
While I cannot give you any specific articles or codes, I'm pretty sure I remember something along the lines of an agent needing to disclose any relations that agent may have to the party they are representing. The argument could be made that you were not in reality at an arm's length of the actual transaction and somehow directly vested in the purchase since it was after all an ex-spouse. The same could be argued with a relative, friend or even repeat investor, but the fact remains if you are ever faced with whether or not to disclose information such as this where there is no logical reason that your relationship to the buyer is relevant in the sale, I would stick with the safe side and disclose, disclose, disclose.