He grew horns for himself
By metaphor: she was unfaithful to her partner or husband.
(Modern Hebrew)
Translation
Expression (Hebrew)
הִצְמִיחָה לוֹ קַרְנַיִים
Definition (Hebrew)
בְּהַשְׁאָלָה: בָּגְדָה בְּבֶן זוּגָהּ אוֹ בַּעֲלָהּ.
(הָעִבְרִית הַחֲדָשָׁה)