Sex and Relationship Control is Common in Cults
One of the brainwashing techniques used in many cults revolve around the leader controlling what kinds of relationships his followers can have and who they have them with. The leader seeks to eliminate any relationships that he cannot control or may connect a person to the rest of society and replace it with a reliance upon himself or the group for a sense of affection. There are a few methods that are used which range from total chastity to total promiscuity or tightly controlled arranged marriages. In this manner the cult leader ensures that none of the relationships occurring are outside of his control, or with people from outside the group whom might provide the vital link back to the rest of society that might make a member disobedient or rebellious. A single male leader with a harem of female followers is actually quite common in cults for this reason.
Most Cults Rely on Isolation From Society
People tend to think of cult members as stupid or gullible, when actually the reality is that they have simply been re-socialized. Cult leaders usually seek to sever ties to the rest of society so that group members lose their ability to compare their actions to the normal baseline. If you have been emotionally, physically, and socially isolated from society for long enough the behaviors dictated by the cult leader begin to seem more and more normal over time. In real life most people would not believe that god wishes for them to medically castrate themselves. But if you have spent the last 15 years of your life in isolation with no socialization or relationships outside of the leaders strict control then after a while it might start to seem like a pretty reasonable thing to do. Everyone else around you are not only doing it, but receive high praise and adulation from both the group and the beloved leader whom you rely on and owe for you day to day existence. "Its not us who are weird, its the rest of the world who are weird."
Cults do not start overnight, and their member's outlandish or disgusting behavior is not something they are required to do right from the start. Members are slowly and methodically cut off from the rest of society and spoon fed a steady series of new expected behaviors and rules. Cults often opt for physical isolation, but emotional and psychological isolation are just as common. Point being, social and physical isolation are often key features of many cults. After a long enough time outsiders become scary and outlandish and your own behaviors as dictated by your leader become normal because you have no moral or social metrics to which to compare your actions except the ones the group or leader provide you.
Cults are not Illegal (USA Based Law)
If your cult is not violating any laws and its members have elected to live under their leader's control there is nothing anyone can really do about it. If the leader says god wants them to shave one eyebrow, paint their noses purple, and dance the Macarena 18 hours a day then there is nothing the authorities can really do about it. Believing or doing weird stuff isn't illegal. Illegal activities are what get cults busted up. SO if the cult leader suddenly decides that the apocalypse is coming and the members need to help it along by killing racial minorities then it ends up on the radar for law enforcement. If members are being physically abused or held and prevented from leaving against their wills the federal government will press criminal charges. Point being, if the cult is not exhibiting illegal activity there is really nothing anyone can do about it. The thing is, thanks to their tendency towards both physical and social isolation it is very very difficult for authorities to prove that these things are happening. For example, if it were in a place where abortion were legal and they simply decided to abort all male fetuses, that is morally questionable, but not illegal. If the members were instead practicing ritualistic infanticide that's another matter. If its not against the law then at-least here in the USA, your cult can believe and practice whatever the hell they want.
Many Cults are Dismantled by the Authorities Because of Defectors
In the heavily fundamentalist sect of Mormon it was thanks to members who were kicked out or who ran away to authorities that it was discovered that the cult was arranging marriages between minors and adults. If the cult is conducting illegal activity and a member is unable to reconcile the behavior as normal or acceptable they might run away and inform the authorities. Often times this comes in the form of some huge moral outrage that a person is not able to justify as acceptable within the group such as a woman being instructed to give up or kill her male child not being able to and running away. If she goes to the authorities and informs them of these activities there will be an investigation and the perpetrators will be charged and sentenced. Sometimes this can bust a group up, but often it just puts the cults on the radar and it takes a series of criminal investigations and charges to take the group down. Often times many members of a group might not even be aware the illicit activity is occurring and will opt to leave when they find out. Additionally, when the leader is removed usually a cult will disintegrate, not always, but without the leadership it is likely. (Sometimes the leader being locked up just encourages the cult even more "See! See! The evil lying outsiders are coming to get us just like the prophet warned us about!")
Bottom line is, cults are often fluid and dynamically changing groups and there is no way to truly predict what a member leaving will do to the group. Some cults are incredibly robust and are able to operate even under federal scrutiny for decades, whilst others evaporate the instant an influential person has enough and leaves. Its all really situation dependent.
