My brother has two cats, twins, as his house. One has cancer and who knows, maybe the vets can prolong his life without just prolonging suffering, maybe it'll be put down soon because it wouldn't be a life worth living anymore (right now, the cat is not in obvious pain).
Of course he and his girl worry how it'll be like for the twin who stays behind, yet still... what the fuck? That's all I can say.
...what the hell? We got 2 cats who were brothers about 6ish years ago, and had to put one of them down last summer when he was still quite young (NOT because we weren't prepared to pay bills, he had a type of tumour they couldn't treat and we didn't want him to suffer). Yes, it upset our other cat, but we never would have dreamed of getting rid of him, he's perfectly healthy and our spoilt baby.
So we got 2 more cats, sisters this time, a few months later and he seems a lot happier with them. Means he has someone to fight over food with, cats like stolen food so much better than food you give them. And now we have 3 happy cats, although I miss my other baby <3