血口喷人 [xuè kǒu pēn rén]

• make an unfounded [scurrilous] attack upon sb.; It's a downright dirty calumniation.; cast malicious words to injure sb.; cast wild aspersions at sb.; make slanderous charges against sb.; malicious words to injure sb.; smite with the tongue; spatter sb. with mud; sling mud at sb.; That's a bloody lie!; venomously slander:

  You're slinging mud at me -- that's a pack of lies!

  你血口喷人， 不讲道理。