I actually do the same thing to the witnesses in the area. I see them all the time. I always say hi, I have to acknowledge them so they know that I won't adhere to their stupid rules on DFing.
When I worked in a local hospital, there was a girl that worked there who I used to be bf's with growing up. I almost died when I first saw her, of course, she ignored me. But, I couldn't let it go at that. So every time I saw her after that I would make sure and say hi. She never replied and always ran off like her hair was on fire!
I don't talk with my witness mother anymore. In my parting words to her I told her she belonged to a cult. I know this word is over-used, but I knew it would hurt her. Since then I have been labeled apostate by the cong. but I rather like the feeling of power that gives me! :)