In 2016, speaking in Hebrew in front of leaders of Israeli settlements in the northern West Bank, Israeli President Reuven Rivlin urged the settlers to “maintain the belief that we have returned to our land, to our homeland, even if our cousins are unwilling to accept this fact”; in an Arabic song first recorded a few years earlier, Palestinian protest singer Jawan Safadi wondered sardonically “who wants to ride us next, once our cousins leave?” Rivlin and Safadi, while using different tones and expressing opposing political viewpoints, both enlisted a common term: “our cousins,” a contemporary colloquial term designating Arabs/Muslims in Hebrew and Jews/Israelis in Arabic. In this paper I examine the historical emergence of the metaphor of Jews and Arabs as cousins, by examining Hebrew and Arabic deployments of the term in the first half of the 20th century, in the context of the colonial struggle in Palestine. I begin by analyzing uses of the term in texts written by early Ashkenazi Zionists. I argue that the idea of an immutable bond between Jews and Arabs was crucial to early Zionism, as a movement that not only sought to de-Semitize and Europeanize the Jew, but at the same time to completely racialize Jews as Semitic. Within this ambivalent Semitism, the metaphor of cousinhood with the native Arabs worked perfectly, as it allowed early Ashkenazi Zionist writers and activists to distinguish themselves from the native Arabs, while concurrently strengthening their own claim of indigeneity by way of an imagined blood relation to the very same natives. I highlight this ambivalence by comparing depictions of Arabs as cousins with an alternative kinship metaphor – that of brotherhood – which was prevalent on the margins of the Zionist movement before 1948, especially among Middle Eastern Jews. Finally, I look at the way in which Palestinian and Arab nationalists responded to the Zionist deployments of the term, with some rejecting it explicitly as a concoction, and others adopting it for their own purposes.