Would you Tell On A Cheating Friend?

It seems the hot topics on this forum is about cheating, and it's always interesting to hear other people's perspective, even if I don't agree with them. Which is why I'm bringing this issue: My girl friends and I have been tight/real close since college. We've been through it all together, and in our circle of friends, everyone is always telling me their dirty deeds knowing that I'm the least likely person to reveal it. The problem is that I don't always want to to know their deeds, cause I know innocent people will get hurt. For example:

One of them is about to get married and she already plans to have an affair with another (younger) man whom she works with. I know because the young man has hit on her several times and she always welcomes his advances. I'm not sure if she's not doing it already. Her fiance and I work together on a publication for football/soccer for a local school and I've known him to be a stand-up individual for some time now. He has been like a mentor to me now for some time because of our mutual interest in soccer.

Another is a sex addict, and I didn't believe the rumor that girls from Calabar had a big sexual appetite until I met her. I have encouraged her to try to get help, but she laughs and says it's not a big deal. She also plans to get married and I doubt her husband can keep her from straying.

A third is a feminist and has little regard for men or their feelings (although i'm not saying there's anything wrong with feminism) I think partly because of what her father did to her mother, (Her mother did not believe in polygamy and her father, being muslim felt he should take more than one wife like the book says. Her mother just got pregant with her at the time and her mom left her dad for another man when he would not agree to monogamy).
 

Personally, I am afraid of the consequences of their actions because those who will suffer from it will likely be their kids. And sometimes I feel like I should slap my friends, but to be honest I love them and I'm not the type to rat out a friend, no matter how guilty I feel. (Even now I feel bad writing this on the web).

I'd like to hear different perspectives on this question: WOULD YOU TELL ON YOUR FRIEND IF SHE/HE WAS CHEATING?

no, don't tell on them, their sins shall find them out jst continue bn da reliable and listening friend