be only visited by green bottle flies after death—a person who has no friends in his lifetime will have no mourners after death
青蝇吊客qīnɡ yínɡ diào kè
青蝇：指苍蝇；吊：凭吊。比喻生前没有什么知己，死后只有苍蝇来吊唁。nobody else attended sb.’s funeral, a lone person who has not had a single friend during his or her lifetime