Outside is the Ocean by Matthew Lansburgh
I think this is a story collection, not a novel, even though these 15 stories are all about the same family and revolve pretty tightly around the relationship between Heike, an emotionally unstable German woman, and her gay son, Stuart. They’re engaging and well written, and,even though their actions are sometimes extreme, the characters are eminently believable. The pieces stand alone as individual stories, and they cohere through layering, more than through progression. (Is that the difference between a novel in stories and a themed or linked collection?) Either way, they’re wonderful stories.