Ironically, all the obsession and preoccupation with the lures of sexuality cause MORE of a "forbidden fruit" mentality that leads to more sexual activity not less!
I speak out of my own experience as I always felt the only reason I got marries was to obtain that "forbidden fruit". Me and the ex were not compatible and it ended up in a loveless marriage where I was only doing my duty to work and provide for my family. Thus my marriage eventually fell apart.
William-Your niece must be approaching 40. The number of available men in the Borg her age are few and far between. She may be afraid that if she doesn't 'take' this guy, she will miss the boat altogether and be forced to spend her life alone forever. It is just the mentality of the JW's. They can't just meet and date and have a nice time, dating is always a means to an end in the Borg.
Yes she is about that age. I was on my own for almost twenty years. I learned the hard way it is better to be happy and alone rather than in a relationship and miserable. I do understand where my niece is coming from as knowing the bad advice she is probably getting from the elders and family, although it did not surprise me when I heard the news.