Mother-in-law has a lung condition and she needs and is supposed to be on oxygen 24 hours a day. But she's stubborn and refuses to use it all the time. As a result her brain doesn't get enough oxygen and her short-term memory is all but gone. That's bad enough but she's also getting nasty with father-in-law, who has had a couple of strokes himself and isn't in perfect health.
And this has all happened fairly recently, or at least, it's worsened rapidly.
Father-in-law is worried about his own memory and not being able to look after his wife, and just takes it all quietly. My two sisters-in-law both live nearby and are being run off their feet - although Mother-in-law will tell you that no-one's been near her for days even though they'll have seen her earlier that day.
There are times I'm glad I'm an orphan.