Here’s a simple problem I solved completely by avoiding it, but maybe you’d like to weigh in anyway: I had friends that got together and dated. Somehow the change in their relationship (from friends to lovers) messed with the politics of our friendship dynamic and things felt awkward. I wasn’t comfortable talking about their coupling but it was right there in the open and totally weird to not talk about. We didn’t talk about it. I eventually got the hell out of there and gradually, after their break-up, all of us stopped being friends.
How could I have handled this better?
LemonVibe 
[Why were you so uncomfortable talking about it? Without some more details, it really looks like it doesn’t make a lot of sense to me. And it’s going to be hard to tell you what you could’ve done better without those detail as well. Right now it looks like there wasn’t anything you could do.
Try to talk about it with them rather than not maybe, but I dunno.
[I agree with Kier, there seems to be some information missing to be able to come up with suggestions on how this could have been handled differently.
The main thing I would say I’m curious about is ‘Why’ did them coupling up make you uncomfortable? Did you feel like you were being excluded in some way? Did they often ignore you when the three of you would hang out? Would they talk about things that pertained largely to the two of them and therefore you had no input to contribute? Would they not consider your thoughts/feelings when making group decisions?
Did you have any jealousy regarding the two of them getting together? Did you have feelings for one of them but never expressed those feelings?
My general advice based on the information currently available…the thing you could have done differently was actually talk about what was bothering you instead of avoiding it.
I spent a majority of my high school/college life being a 3rd, 5th, 7th wheel in various groups of friends so I can completely understand where you are coming from. In my circle of friends at least two of them would eventually begin dating and then eventually break up.
In the few instances where I felt uncomfortable I had to determine if I felt that way because of my own thoughts/feelings or if it was because of something one of them said or did. If the latter, then it was something I most often would talk to one (if not both) of them about.
[You can’t expect that everything will remain the same when a situation like that occurs. You’ll have to give them more space as they develop their relationship, because they are going to want to focus on each other when they’re together. Instead of constantly trying to hang out as a group of three, spend more time with each of them individually, but branch out to other friends, as well.
Once the relationship matures, it’s easier to spend time with a couple. But until then, you just need to recognize the change in dynamics and not feel resentful of it. It’s no different than when anyone begins a new relationship, and no matter how much time they continue to spend with friends, it isn’t the same amount as it was previously because a new relationship needs time and attention.
[I think it may have been awkward for all 3 of you, not just you as the 3rd wheel. Your friends probably felt weird about getting together behind your back (at least at first–I’m sure you didn’t witness every aspect of their courtship right from the beginning), and I’m sure there was at least a split second when you thought “why them, why not me?” just as a curiosity, not necessarily because you were actually interested.
I’m sure there was a little jealousy involved. They became closer as a twosome than you all were. You felt left out. As they got closer, you felt further from them. When that happens, it’s harder to just TALK about stuff. It’s like that in any relationship. Things get weird, and then you stop talking about it because it’s too weird. It’s cyclic.
I think what you could have done was give them a little space. In the beginning, letting them hang out on their own most of the time would have been a good move. You could have seen them each individually, but the group dynamic is always going to change when two of three become involved. There’s nothing you can do about that. I think “getting the hell out of there” wasn’t the right thing to do. After all, they were still your friends. And maybe if you had continued to hang out with them (at least individually), then after the break-up, you’d still be friends. You would have been the foundation of the friendship between the other two.
[I’ve been in this position before. In high school, two of my best friends (as in, the three of us hung out together ALL the time) started dating. I was devastated, and I tried to do everything in my power to still maintain our little “posse.” They even tried to be gracious about it and include me as much as possible.
Ultimately, I realized (okay, yeah, I realized this like 10 years later), my presence was just awkward for everyone. What I should’ve done was back out of the group and find new friends. Now, I only look back on that whole period of my life and roll my eyes.
Anyway, I don’t think there’s anything you could’ve done to handle the situation better. It’s a shitty position to be in, and when it happens, I really do think your only option is to let the friendship go. This isn’t to say that you can’t become friends with them again at some point, but it WILL be a different friendship. I don’t think there’s any way it can ever go back to the way it was.
[Some sharp instincts in this thread. I did feel a little jealous and kind of betrayed. I wasn’t going out with anyone at the time and they were both my friends who I would expect to give me a heads up about their feelings. Instead, it just happened and caught me off guard. I admit completely that I’m not the best at expressing my feelings verbally (I do better when I can write them out), but maybe they could have got the ball rolling and talked about it first? I don’t know. We were all pretty young, so maybe none of us had the vocabulary to deal with what’s still a complicated issue in my opinion.
Giving them space is what ends up happening no matter what (staying or getting the hell out of there) so maybe there is no solution and the friendship can’t be maintained. It wasn’t. Sad.