When I was 17/18 I got involved with a married brother who was 25 years my senior. It was entirely initiated by him; I didn't think of him as anything other than a father figure before he told me he was in love with me (we worked together). Our (secret) relationship lasted about two years, during which he completely dominated every aspect of my life, including picking out my clothes, choosing what music I could listen to, forbidding me from watching TV or movies, refusing to allow me to wear makeup or jewelry, and deciding what I could eat and who I could hang out with. The fact that all of this happened in secrecy without anyone knowing (although we did sit through a number of meetings with the elders towards the end of the two years (during which we both denied everything) and I believe his wife was pretty suspicious) is all the more amazing. Although he refused to leave his wife, he told me that he would commit suicide if I ever married anyone else. My parents wondered what in the world was causing this radical transformation in all of my habits. Even after leaving the relationship (I left and moved to a different state because I was afraid of being disfellowshipped, not because the relationship was abusive; I didn't believe it was) I felt that I was absolutely in love with him and that we were meant to be together, that all these changes were things that I WANTED, and that we'd be together in the new system (his wife was an unbeliever). Afterwards, I spent years consumed by the guilt of the fornication and by the fear that he would somehow find out that I had worn earrings or watched a movie or committed some other "sin" when my strict habits started to slip a bit in my new home.
Now, 14 years later, out of the borg, and married to someone my own age and completely un-domineering, I am amazed at both how naive I was and how much damage the relationship caused me emotionally.