אבן העזר קע״חEven HaEzer 178

Se’if 1א׳

הַמְקַנֵּא אֶת אִשְׁתּוֹ, וְנִסְתְּרָה, וְאֵינוֹ יוֹדֵעַ אִם נִטְמֵאָה, אֲסוּרָה לוֹ. וּבִלְבַד שֶׁיְּהֵא הַקִּנּוּי וְהַסְתִירָה כָּרָאוּי, וְאָז הִפְסִידָה כְּתֻבָּתָהּ, אֲפִלּוּ מֵת קֹדֶם שֶׁגֵּרְשָׁהּ:

One who legally expresses jealousy over his wife and she is secluded but he doesn't know if she was defiled, she is prohibited to him. And this is true as long as the expression of jealousy and seclusion were performed as the law requires. And in such a case she loses her ketubah, even if he dies before he divorces her.

Se’if 2ב׳

כֵּיצַד הַקִּנּוּי, אוֹמֵר לָהּ בִּפְנֵי שְׁנַיִם: אַל תִּסָתְרִי עִם אִישׁ פְּלוֹנִי, אֲפִלּוּ אִם הוּא אָבִיהָ אוֹ אָחִיהָ אוֹ כּוּתִי אוֹ שָׁחוּף פֵּרוּשׁ, שֶׁאֵינוֹ מִתְקַשֶּׁה (טוּר), וְהוּא שֶׁיְּהֵא גָּדוֹל. אֲבָל אִם אָמַר לָהּ: אַל תִּסָתְרִי עִם פְּלוֹנִי, וְהוּא קָטָן אוֹ בְּהֵמָה, לָא הָוֵי קִנּוּי. וּמְקַנֵּא לָהּ בֵּין אִם הִיא אֲרוּסָה בֵּין אִם הִיא נְשׂוּאָה אוֹ זְקוּקָה לְיָבָם:

How is jealously [legally performed]? He says to her in front of two [witnesses]: Do not be secluded with so-and-so? Even if he is her father or brother or a non-Jew or a "shahuf" (one who cannot get an erection, Tur), as long as he is of majority age. But if he said to her: Don't be secluded with so-and-so, and he is a minor or an animal, this is not legally performed jealousy. And he may profess jealous over her whether she is betrothed or married or awaiting levirate marriage.

Se’if 3ג׳

קְטַנָּה שֶׁהִשִּׂיאָהּ אָבִיהָ וְזִנְּתָה לִרְצוֹנָהּ, יֵשׁ מִי שֶׁאוֹמֵר, שֶׁאֲסוּרָה לְבַעְלָהּ. לְפִיכָךְ מְקַנְּאִין לָהּ, כְּדֵי לְהַפְסִידָהּ כְּתֻבָּתָהּ. וְיֵשׁ מִי שֶׁאוֹמֵר, שֶׁאֵינוֹ נֶאֱסֶרֶת עַל בַּעְלָהּ, אֶלָּא אִם כֵּן הוּא כֹּהֵן. הַגָּה: גְּדוֹלָה שֶׁזָּנְתָה בְּשׁוֹגֵג, שֶׁסָּבְרָה שֶׁבַּעְלָהּ הוּא, וְהוּא אַחֵר, מֻתֶּרֶת לְבַעְלָהּ יִשְׂרָאֵל (הָרַמְבַּ"ם פכ"ד דְּאִשּׁוּת). אֲבָל זָנְתָה שֶׁסָּבְרָה שֶׁמֻּתָּר לִזְנוֹת, הָוֵי כִּמְזִידָה וַאֲסוּרָה לְבַעְלָהּ יִשְׂרָאֵל (מַהֲרִי"ק שֹׁרֶשׁ קס"ז). אִשָּׁה שֶׁנִּתְיַחֲדָה עִם אֲנָשִׁים בַּדֶּרֶךְ, וּבָאָה וְאָמְרָה: נִתְיַחַדְתִּי וְנֶאֱנַסְתִּי, יֵשׁ אוֹמְרִים דְּנֶאֱמֶנֶת, בְּמִגּוֹ דְּאָמְרָה: לֹא נִבְעַלְתִּי, וְיֵשׁ אוֹמְרִים דְּאָבְדָה מִגּוֹ שֶׁלָּהּ, הוֹאִיל וְנִתְיַחֲדָה שֶׁלֹּא כַּדִּין (שְׁנֵי הַדֵּעוֹת בְּמָרְדְּכַי פֶּרֶק שֵׁנִי דִּכְתֻבּוֹת):

A minor girl whose father married her off and she willingly fornicated, there are those who say she is prohibited. Therefore, they can profess jealousy over her, in order to cause her to lose her ketubah. And there are those who say that she is not prohibited to her husband unless he is a priest. Hagah: An adult who accidentally fornicated, thinking he was her husband but he was someone else, is permitted to her Israelite husband (Rambam, chapter 24, Hilkhot Ishut). But if she thought it was permitted to fornicate, this is like one who does so intentionally and she is forbidden to her husband (Maharik, root 167). A woman who was secluded with men on the road and she came back and said: "I was secluded and I was raped" there are those who say she is believed with a "since" argument, for [she could have said] I did not have relations. And there are those who said she loses the ability to make such an argument, since she was illicitly secluded (both opinions are found in the Mordecai, second chapter of Ketubot).