Saul Glazer and Morris Unger--their paths cross when young, before the Depression: Morris' distant cousin Ruth promises to marry each of them . . . but finally she breaks Morris' heart by choosing hugely successful negligee manufacturer Saul instead of unfashionable painter Morris. (He mostly does Degas-influenced dancer studies.) Thus, while Morris heads for Paris, Saul (along with Ruth now) moves to Park Avenue. And over the next 50 years the two men's destinies will be thoroughly dissimilar, but they'll occasionally see each other. Ruth (who has turned into a selfish, manipulative, self-righteous woman) visits Paris with Saul and buys a painting from Morris. Morris has to leave Paris before the War, leaving behind a beloved model/mistress and their grown son. But, though Yaffe (The American Jews, Nobody Does You Any Favors) does extract some engaging family complexity (as well as Saul's business savvy) from this parallel-lives premise, the prose is limp, with main players who are both a bit clichÃ‰d and not exactly believable. (Morris' artist-thoughts are especially unconvincing: ""That Italian--what was his name?--peculiar little man, never sober, killed himself with absinthe--Modigliani, that's it. Those matchstick women he specialized in never appealed to me at all."") And the droopy ending, with Saul and Morris both old, is an unpersuasive brief for survival-through-mediocrity. Unpretentious, unexciting storytelling withal--occasionally generating some rich Jewish-family texture.