Make a list and view that list instead of your news feed. The added bonus is the posts show up in reverse chronological order, without all that "top stories" nonsense, and you don't get the ticker and other annoying distractions you get on the newsfeed. You can also post to just a specific list (or even multiple lists, I think) rather than to all your friends. So from K's POV, you're still friends, you just aren't posting or commenting on her posts anymore.