My Boss is Cheating on His Wife, What Should I Do?

Dear Experts, I just got a job working for a guy that has been my idol for awhile now. I've known him for years, kept in touch with him after I graduated, etc. I was so psyched when he offered me a job a few weeks ago at his company as a sort of assistant. He's a really busy guy, has a couple of businesses, is very well-known and successful in my town. So, imagine my surprise when I learned this week that A) he's cheating on his wife, and B) he expects me to cover for him when she calls. I don't know what to do. I know his wife, she is very nice. I think it's terrible that he is cheating on her, but I don't know the whole story, nor do I want to know. I just want to do this very cool job (I'm getting paid well too), learn a bunch, and hopefully, move on and up in his company. I haven't told ANYONE about his - not even my girlfriend because she would tell me to quit. Also, I would hate for it to get out and be my fault. What's your advice? Our Twitter Advice Project (T.A.P.) is no longer an active campaign. To find an answer to the above question, please use the "Search" box in the right-hand column of this website.