Next time she texts her OM in front of you and starts in with the giggling and all the rest, consider walking over, saying nothing, taking the phone from her, and slowly but with purpose crushing it under your foot, then calmly walking away.
Funniest thing I've read on here in a while. Let us know how that goes.
There are moments in this life when you are so confident in the rightness of your actions, that not even for a second do you consider the option that you might be wrong.
