This field research reveals that the behavior of deviations due to “besanan” (having relationship between parents whose children are married to each other) that occurred in Juwet village, Ngronggot sub-district, Nganjuk district, as well as its analysis of the Islamic family law perspective. “Besanan” as a pre-marital process is a hereditary tradition in most Javanese communities, especially East Java, including Ngronggot District, Nganjuk District. None of the people do not carry out “Besanan”; even though there is no argument that legitimizes it from both the Qur'an and the hadith. Unlike the “Khithbah” which clearly has a variety of Hujjah. However, in the next stage, Bataan has legality. Initially only a tradition turned into a good Shari'a to do. But unfortunately, “Besanan” brings and has no good implications on the pattern of the couples' promiscuity. Actions that basically prohibited by the religion are no longer abandoned on the pretext of having obtained permission from the guardian and have been "future husband/wife". In the analysis of Islamic law, this phenomenon cannot be claimed as right. There are various verses of al-Qur'an and al-Hadith that can be used as a knife for analysis. Even the science of Ushul Fiqh and the Law of Fiqh has sentenced the law to illegitimate actions