When someone acts in a reasonable fashion towards you or your colleagues, while being consistently pointing in conversation and comments towards the negative things in life.
Like my mom, she is cool sometimes, but she complains about everything. So she will be chill to be around, but she always talks about how something isn't to her standards. Blah.
She's so coolsuck...
Or that one friend you have that acts like the character that Charlie Day plays in the movie Horrible Bosses, worry wart; but a good friend.