In return they have to stay away from you once you make it clear you think their beliefs are beyond whacky.
The result - you don't see each other, but you still get to go to all the fun things like birthdays etc without that freak being there. Win!
Adam: Nah man, he's a JW, we are keeping our distance.
Bob: Sounds like some serious Jehovah's Splitness there bro?
Adam: Damn right, it's awesome.