Friend's husband may be having an affair-what to say?Pls Hlp?

This could be many things. Although you have made some pretty valid observations. Or maybe the observations were those given to you from your friend(You didn't make this clear). Either way it doesn't matter, there is a reason for the secretive phone calls and the all of a sudden wanting to go out. The reason why this is important is because it's a marriage. Yes, your friend needs to know. Whether you tell her or not is not the question. In my opinion, you shouldn't. For many reasons: she might not believe you, she might resent you telling her, it may not be true, and many more. Keep it cool and support her. Maybe take her out, go out with her and have fun. Have a woman's night out. If it is an affair, it will get exposed. Just be the there for her if she needs it.