shit stirrer
noun [ C ] mainly UK offensive uk/ˈʃɪt ˌstɜː.rər/ us/ˈʃɪt ˌstɝː.ɚ/
（尤指泄漏别人秘密的）麻烦制造者，搅屎棍
someone who makes trouble for other people, especially by making known facts that they would prefer to keep secret
He didn't need to tell her that - he's just a shit stirrer. 他不必告诉她的——他可真是爱搅和。