kurt and sebastian are in a relationship, but kurt doesn't think sebastian will want to or will be capable of remaining monogamous. so he tells sebastian that he wants to watch him get it on with someone else. sebastian agrees to it. after many times, it comes out that kurt thinks of it as cheating and that he never actually wanted sebastian to do it, and sebastian is so hurt that kurt would trick him into hurting his boyfriend. they talk it out, and kurt wants to understand how sebastian sees it, so sebastian devises a way (maybe by having kurt sleep with someone else?). I think i read it on livejournal in a few parts. Would really appreciate the help!