A term used to describe self-righteous attitude through the phone, whether it be spoken or texted. Phone Sass is usually accompanied with the feeling you are boned (not literally), or have been ratted out. Phone Sass also applies to AIM, Skype, or any method of contact over long distances. Phone Sass is not quite as bad as face-to-face sass, in which you can't easily take a bathroom break or run to grab a drink like you can while on AIM.
Ugh, her Phone Sass is really bugging me. Why did he have to go and tell her that?