loyalty

sometimes you're faced with a really hard decision.
sometimes you know something and you know that it could affect someone else, someone you're close to.
sometimes you were involved in those somethings you know. even if you yourself didn't do anything to betray anyone.
but what do you do after it's all been said and done.
do you fess up? knowing that whoever could be affected by it deserves to know?
or when you're sure that they'd never find out otherwise, do you just let it be?
me? i'm the kind of person who fesses up. loyalty and trust are really important to me.
i live by a general rule of  "would i want this to happen to me?"
meaning that if i wouldn't want it happening to me i wouldn't do it to anyone else.
i've known people in the past who aren't so great at following this. who have a different moral code than i do. which is fine. ethics are different for every person. you can't just make one rule and expect it to apply to everyone equally. it doesn't work like that.
but i live by a "do unto others mindset"
that doesn't make it any easier to fess up, when you know something. it's still almost impossible to do. i'll admit sometimes i get a little selfish and think what the reaction towards ME will be. will i be a rat? will i be seen in a bad light? will i no longer have this person in my life?
but my loyalty is to my friends and myself. and if they don't want me in their life, then i as a friend must respect that.
but why does it have to be so hard?!?!?!