I's assuming that your use of the word friend is not the same as Acquaintances. If you don't really know them well, then you can deny knowing the truth, beucase you shouldn't care about anyone pointing fingers at you, when the truth comes out. If these people are really close friends, then here's my answer: I know that I wouldn't be friends with someone that would cheat with another friends boyfriend. I would be livid if someone I called a friend knew that two people in my life had betrayed me. I would completely remove all 3 parties from my life if it were withheld from me for a long period of time. I would appreciate a friend looking out for me and telling me the truth. So, even if you deny knowing, you can't be guarnateed that your friend will believe you. So you withheld information, then lied about knowing the truth... seems like a dangerous web to be weaving. I know you didn't do anything wrong, and the cheaters have put you in an unfair position, but you should think about bigger picture and what kind of friend you want to be. Personally, I will never accept the answer that Ignorance is bliss, people that say things like that are afraid to live their lives honestly.

In this conflict, you have to make a choice. And you will have to support the consequences of your choice. I don't think it makes any sense, if you choose to keep your mouth shut, to entangle yourself and other people in a further web of lies. If this comes out, let them say what they want and if the friend having been cheated on asks you, I would suggest that you just admit the choice you had taken.

Thank you to all three of you, your answers have helped. The situation is quite complicated, there was not nearly enough space to write the whole complexity of the question. Can you tell me if there is anyway we can have private discussions? i'd like to go into more details without posting on the general internet site to preserve privacy. That is of course if you are willing too. Thanks

It's difficult and while I agree with LilyWhisper on principle, it's too late when someone has told you something then asks you not to tell. Ideally, you should have been asked if you would be prepared to share this confidence but most people are not moral gurus:( In your place I would ask your first friend (the cheater) not to tell you anything more about it and say that if you are asked outright you will have to be truthful. You don't have to feel obliged to anyone other than your self. My mother used to say, 'To thine own self be true'. That's all we have in the end.

Actually just to clarify, the friend that told me has not asked me to keep the confidence. In fact she told me that she didn't care if i told the other friend because she didn't want to put any pressure on me. It is me who doesn't want to be involved and as such have requested that she not volunteer the information to our friend that i know. Whether she denies that i know if directly asked? i don't know whether i am asking her to do that.. i'm not too comfortable with that either. But i find i am annoyed with the situation i have been put in. Just to clarify also that the girlfriend and i used to be very close, but have had our own problems and so have drifted and are in little contact at the moment. The 4 of us (including the couple) are all in seperate countries now too.

Ok another little bit of news i didnt' tell you is that this girlfriend isn't so sure about her 3 year relationship with her boyfriend anyway, and often says she wants to break up. also they are now living on opposite sides of the world. Oh, i wish it was black and white!!

Well, you should probably find out if it's true in the first place. Have you talked to the boyfriend about it? You should probably ask him. You could also give them a time frame to tell, and if they don't tell, you will.