Remember the Episode on Friends when Rachel began dating Danny? After a few short dates, she realized that he had an unusually and uncomfortably close relationship with his sister?
Or how about the fact that Joe Simpson is always getting way too close for comfort with his daughters Jessica and Ashlee? It's got to be hard for other people to be around these types of families. It really makes you wonder what kinds of morals and boundaries they have. In some parts, this kind of intimacy would be illegal.