Would you break the news to your best friend if it hurts her?

As a friend, maybe I would just give her an idea about what I found out and not really tell her the news because it would be more approrpiate if her boyfriend would be the one who's going to tell her about it if something's going on. It also depend on how you're going to tell her. If you do it calmy, then I think it wont trigger the emotions that much. At times liek that, she has to be strong and you should be strong for her too. And maybe the best way to that is just be with her and listen to every word she says.

that's a hard one, but i know my best friend, and i know how she's gonna react. I'll definitely tell her about it, and I know she'll trust me. I'll ask her to find it out for herself though, so that there's real evidence for her to use as a reason to break up, because I'm sure she's going to break up with the guy the minute she catches him. By the way, my best friend is my sister.

OMG this is so hard. I would probably first ask her "if you saw my boyfriend with another girl would you tell me" or ask her if "she would you want to know?" Take it from there then depending on her answer. Its a very hard thing because some friends will get angry at the person who tells them what they saw and others will appreciate it so they don't continue to waste their time. I feel so bad for her.

I don,t know what the words would be, but i will definately tell her. I would try and put it as subtle as i can, but no matter how it will be said, unfortunately it will hurt like hell. But i feel, rather privent your friends from making mistakes, they will later regret, than leaving them to be hurt, very badly.