So are you being level headed when taking a video of your friend's BF and then using it to convince him he's being cheated on? What's the motive? What is the structure and function of seeing someone else cheat on someone else?
You're posturing as if you're being cheated on. But you're not in THEIR relationship and using a video to expose his infidelity is a very big emotional manipulation.
I think you need to mind your own business. Unless you're jealous or have a solid relationship with both men that has given you clear and compelling evidence that they want you that deep in their business, you should erase the video, and stop making drama.
That is the strangest way to think of this situation.
You would assume that someone is jealous because he is telling his friend when he's being cheated on?
Does there have to be a "motive" other than just trying to look out for your friends? Is that not a good reason enough?
How would you fault the drama to be made at the OP when it's the boyfriend who's cheating?
If the worse case scenario happened and his friend 'caught' something from cheating boyfriend would that not be somewhat his business as a friend to look out for him?
Hypothetically, if you knew your friend was in an abusive relationship, would you just leave it because it's not "your" relationship?
To each their own I suppose, but I don't see how sitting on the fence helps anybody, and if you can't get help from your friends then something is wrong with the world.
Again, as per what the OP posted it's not like he was spying on his friend's boyfriend waiting for him to cheat, he came across it by chance and so I don't think it's him being intrusive or nosy if he happened to see it by chance.
Sometimes when you happen to see something there is some kind of level of responsibility especially when it happens to affect someone you care about and I think turning a blind eye is as silly as egging it on in some cases.
I don't know how clear and compelling an actual video of him cheating with another guy can get any more clearer. Not that I'm saying it should be uploaded to youtube, as I said I think these things should be handled gracefully.
If you're thinking that he would be 'ruining' his friend's relationship, again the blame would be on the boyfriend for cheating and why would you be okay with your friend living in a 'fraud' happiness. Based on what the OP said, he knows that they are 'supposed' to be in a monogamous relationship.
Anyway andyb91, there you go you have two different opinions already. Up to you what you do from here. I believe that you should treat others the way you would want to be treated, so based on that I'd want to know if I was being cheated on therefore I would say something. Probably in a 1 on 1 conversation keeping in mind the sensitivity of the situation.
P.S. If your friend were to actually get upset that you told him his boyfriend was cheating on him, I wouldn't say it's because you're a bad friend, maybe he's got issues he's got to deal with too but I definitely wouldn't view your actions as a bad friend.