Help - Cheating Friend

Me101

Hi, I posted this in the Romantic/Dating threads but I'm going to post here to see if I get more replies from diff ppl -

My best friend has been cheating on her husband with the same guy for several years. She and hubby have only been married for about 4 yrs, but prior to their wedding she was cheating on him as well. She has also had sexual encounters with bosses, coworkers, and the like. I think she's probably messed around with at least 5 people behind her hubby's back.
Her husband is a good friend of mine, but I am loyal to her because I knew her first. Dumb huh?
Anyway - long story short - she put me in an odd situation today - I had to cover for her and didn't know I had to do so. I called her cell phone, and her husband answered it. 3pm in the afternoon, he says she's sleeping. I asked "still sleeping from last night, or napping?" and he replied that he didn't know... and said she left the house early that morning around 5:30/6am to go to a department store, and he went to work at 8:30am, when he got home that's when he found her sleeping.
Well I know she didn't go to the store - 3 reasons -
1) we already WENT to that same store LAST NIGHT and she got everything she needed while we were there, not to mention we didnt get home til almost 1am.
2) the guy she is cheating with has an event every friday night that goes til about 4am, so you can pretty much figure that while hubby was asleep, she was on the phone w/him setting up a breakfeast nooky call.
3) she told her husband (who originally told me) that the store opened at 6am. I know the store opened at 7. I called them, there was no special "doorbusters" event at 6am.

I mentioned how I felt a tiny bit on the phone and then she got defensive and got an attitude, so I let her go. I then text msg'd her saying "I'm sorry, I just feel odd because I know the store didn't open until 7."
She's not only lying to her hubby, but now she's lying to me, putting me in awkward situations, I don't know how to deal with this.
I know it's really easy to say drop her, but that's going to be really hard considering we work together - at a job SHE got me, with a boss who adores her, and will fire me if I piss her off. And I can't chance that, I can't get another job.



I hate that she's lying to me, and I can do nothing about it because it will cost me my job.