Jerusalem Talmud Yevamot 13.11

משנה: מִי שֶׁהָיָה נָשׂוּי לִשְׁתֵּי יְתוֹמוֹת קְטַנּוֹת וָמֵת. בָּא הַיָּבָם עַל הָרִאשׁוֹנָה וְחָזַר וּבָא עַל הַשְּׁנִיָיה. אוֹ שֶׁבָּא אָחִיו עַל הַשְּׁנִיָיה לֹא פָסַל אֶת הָרִאשׁוֹנָה וְכֵן שְׁתֵּי חֵרְשׁוֹת. קְטַנָּה וְחֵרֶשֶׁת בָּא הַיָּבָם עַל הַקְּטַנּה וְחָזַר וּבָא עַל הַחֵרֶשֶׁת. אוֹ שֶׁבָּא אָחִיו עַל הַחֵרֶשֶׁת לֹא פָסַל אֶת הַקְּטַנָה. בָּא הַיָּבָם עַל הַחֵרֶשֶׁת וְחָזַר וּבָא עַל הַקְּטַנּה אוֹ שֶׁבָּא אָחִיו עַל הַקְּטַנָה פָּסַל אֶת הַחֵרֶשֶׁת.

MISHNAH: Somebody was married to two underage orphan girls and died. If the levir had intercourse with the first one and then had intercourse with the second, or his brother had intercourse with the second, the first one was not disabled. The same holds for two deaf-mutes. An underage girl and a deaf-mute. If the levir had intercourse with the underage girl and then had intercourse with the deaf-mute, or his brother had intercourse with the deaf-mute, the underage girl was not disabled. If the levir had intercourse with the deaf-mute and then had intercourse with the underage girl, or his brother had intercourse with the underage girl, the deaf-mute was disabled.

הלכה: מִי שֶׁהָיָה נָשׂוּי כול׳. אֲפִילוּ לֹא בָא עַל הַקְּטַנָּה פּוֹסֵל אֶת הַחֵרֶשֶׁת. שֶׁאִילּוּ לֹא בָא עַל הַקְּטַנָּה וָמֵתָה הָיָה מוּתָּר בַּחֵרֶשֶׁת. וְעַכְשָׁיו שֶׁבָּא עָלֶיהָ אֲפִילוּ מֵתָה פָּסַל אֶת הַחֵרֶשֶׁת.

HALAKHAH: “Somebody was married.” Even if he did not have intercourse with the underage girl, the deaf-mute is disabled. If he did not have intercourse with the underage girl and she died, he would have been permitted the deaf-mute. But now that he did have intercourse with her, even if she died he had disabled the deaf-mute.