cry (someone) a river
Said sarcastically to someone whose whining, complaints, or tears fall on unsympathetic ears. Most often said as "cry me a river." You can cry me a river, but you're still not going to that party tonight! A: "It's so unfair, I work so hard, but I only get a raise every two years!" B: "Oh, cry me a river, I haven't gotten a raise since I first started working!"