Jennifer's husband has died in his 60s. Back for the funeral and to make arrangements are her two children, Mary and John, and their respective partners David and Caroline. At supper the night before the funeral an argument starts. Mary reveals that she's been having an affair. Whose POV is best suited to the scene?
There are pros and cons with most of the characters. Jennifer is the grieving widow, but she isn't directly affected by the announcement and neither is John. David is affected, but until Mary's announcement, he's slightly on the sidelines as a non-blood relative. Caroline is a non-blood relative too, and she doesn't have direct involvement in Mary's announcement. Mary is probably the best choice because not only does she have a secret to keep for the first half of the scene, but she also has to deal with the fall-out from her announcement.
Now change the scenario. It's as before, except Mary's lover is Caroline, her brother John's partner. Whose POV?
Both Mary and Caroline have secrets to keep in the first half of the scene, and fall out to deal with after the announcement. I'd be tempted to have the first half of the scene from Mary's POV, then have the aftermath in Caroline's as she deals with a) John's reaction and b) her own reaction to Mary revealing their secret. Both John and David are affected, but not until Mary's announcement.
Now change the scenario again. We're back to the first one, where Mary's lover is someone else outside those present. This time, David and Caroline are also having an affair, which no one else knows about. Whose POV?
Mary has her secret, John and Jennifer aren't directly involved. I'd go for either David or Caroline's POV because they've both got a secret to keep hidden, then after Mary's announcement their situation changes. Caroline could realise David might become free to marry her, which could be a good or a bad thing. David could be shaken into realising that it's really Mary he loves, or he could think he's just been landed a Get Out of Jail Free card - he can now leave the marriage and be with Caroline.
In general, who ever has the viewpoint should be a character that a lot - if not the most - is happening to. There are a couple of exceptions to this - which I'll deal with tomorrow.