There are only a few things that really piss me off about other people.
Oh sure, I get annoyed a lot, but to really set me off you have to (a)treat people like shit, and (b)do it on purpose.
Once example of this is when you take for granted someone that you ostensibly care about, then whine and moan when they don't ask "How high?" every time you ask them to jump.
A little bit of attention can go a long way for people that don't have the highest self-esteem to begin with, and to ignore them until it's convenient for you, then to expect Pavlovian responses every time you ring a bell, is just flat out rude.
I watched this situation play out today for about the millionth time, and finally the mistreated person spoke up about it.
Yay for her.