Pat Pat.
Personally I feel that backstabbing happen all the time all over
the world, just a matter of how ppl gonna take it when it happens
to them.
I have been backstabbed a lot of times by close friends, friends,
colleages, etc... To me it's just simply a cup of tea, and kind of
get used to it already 
Thou sometimes it can be very hurting to know that you have
actually been backstabbed or betrayed by ppl closed to you but what
to do, that's life.
And life itself is not an easy route, maybe all these are just
tests to make us stronger and view things in different angles...
life lessons, etc...