My worst is being constantly reminded/nagged to post in something. Honestly it makes me want to rp with someone less out of spite if they do that. I'm more than willing to give heads up if I'm going to vanish (nowadays at least, since before I was a very flaky person Im ashamed to admit), so trying to guilt me or be passive-aggressive about me not posting will pretty much guarantee I won't be rping with you very much in the future.