So sad to hear this about you and your little brother. Similar happened to me once. My youngest sister was 16 and I was already DF'd for a couple of years. Somehow we got in touch and she told me she didn't want to be a JW. At that time I also had email contact with my parents for a short while. Apparantly they thought at that time me being DF'd wasn't a problem. One day my I stopped by the house of my parents (we were in the neighborhood while we lived 1,5 hour drive away) just to see and hug my little sister, and we did. She met my then fiance and it was all very nice. My parents did approve and knew that I had met my sister on their doorstep.
Not long after that I asked my parents through email if I could pick up my sister for a drink somewhere. Just to have an hour or so together, just the two of us. I had no intention of talking about the WTS, just wanted to get to know my sister a little bit better and hear her stories about school and being a teenager. (I'm twenty years older and was already married and moved away from my parents house by the time she was born). My mother reacted like stung by a bee... she asked me if I had secrets, why I didn't want to meet my sister in their home, what was I planning???? In fact I wasn't planning anything, had nothing to hide, just didn't want my to get my parents in any trouble with the ever spying brs. & srs. for entering their house for a social visit. My father had said earlier on that he would allow me to stay in touch with my sister, but suddenly he had changed his mind and he told me that I had to wait until she was 18. I was so disappointed!!! And I told my father that he was a liar, because he first said something quite the contrary. All of this only because of the weird suspicions of my mother!
My accusation of him being a liar pissed him off, as did my mother. The email contact stopped right then and there, not after he sent me a line that I'm egoistic and that he 'finished the book 'Bruja' and threw it away' (very hurtful I can tell you, since he actually said he was throwing ME away, his own daughter).
The only time I ever saw them again was with the funeral of my grandmother two years later, where they pretended that everything was fine (see earlier posting about that). After I wrote about that on my blog they started to hate me. Since then my sister has turned into our parents 'best daughter' and a JW-extremist and a clone of my mother with the same narcissistic destructive behaviour. She is now joining my parents in shunning my JW-brother and his family, because his fifteen year old daughter recently gave birth to a baby... oops... tiny mistake from my little niece!!!! (So glad I can 'see' all this from an enormous distance and don't have any part in this whole disturbed family anymore!)