well when tanya and max met and strated seeing each other she didnt know he was married until she was madly in love with him and it was too late, i know that doesnt make it okay but its not like she knew about rachel and bradley from the start.
Bradley needs to get off his high horse now, as you have said stacey never cheated on him and sure max is a married man but bradley didnt seem to bother before, when he knew about stacey dating a married man