Beware of the sheep in wolf's clothing.
In business and in life there will always be people that pretend to be your friend and then talk differently behind your back, they are really just in it for themselves.
The sad thing really is " they" truly think they are pulling the wool over your eyes and think they are smarter by using you and the situation(s) to benefit them but most people can see right through them.
Don't get me wrong, some may take longer to show their colors then others but none the less they will eventually fall because their faith and foundation is a house of cards.
If you want to build a solid foundation simply tell the truth and work to help others NOT use them for your own good and try to remember what goes around comes around.
How do you work with those you do not trust ?
Do not hurt yourself, be smart, do not lower yourself to their level- get the information that you need and do your job.
That said choose your words wisely to those you cannot trust and do not give them fuel, get what you need and do not gossip, that can be easier said then done because being hurt you will want to vent and let others know but let it go , as I have said in past post justice will be served, it always comes around.
Do not evolve into a wolf, be better then that, build a solid house not one of cards and one you can be truly be proud of.