הלכה על נדרים 180:4

And from [this], we learned that one who has mated with a beast does not become a licentious woman, even though she is [punishable] with stoning - as it is specifically the intercourse of a man that makes her a licentious woman (Yevamot 59b). And so [too,] if she had intercourse when she was still a menstruant with someone to whom it is fitting for her to be married; she does not become a licentious woman with that, even though it is [punishable] with excision. And likewise [in a case of] one who has intercourse with a single woman - even if she was a prostitute, meaning she made herself available to all - she does not become a licentiousness woman so long as she has not had intercourse with someone she is forbidden to marry, meaning that she is a sexual prohibition for him. And even prohibitions of [only] a negative commandment or even [those forbidden by] the obligations of a positive commandment are included in this prohibition. And therefore they said that if one of [the following] - a [gentile], a slave, a natin, a mamzer, an Ammonite or Moavite convert, an Egyptian or Edomite [convert] of the first or second [generation], one whose testes are crushed or whose member is cut off - had intercourse with a Jewish woman, he makes her into a licentious woman and she is disqualified to the priesthood. And if she is a priestess, she is disqualified from the priesthood. And so [a woman] who has had intercourse with someone who makes her a licentious woman is disqualified on account of [being] a licentious woman, from when he inserts himself in her - whether through rape, through consent, through inadvertence, and whether in her [conventional] way or not in her way - and [that is] only when she was three years and a day [old] and above, and the [man] was nine years and a day and above. And also from the matter of the commandment is that which they said (Nedarim 90b) about the wife of a priest who says to her husband, "I was raped," - and even if a witness testifies to him that it was so, like her words, that she was [made] licentious - that she does not become forbidden to him with this. As we say, maybe she put her eyes on someone else [and is seeking a pretext for divorce]. And nonetheless, she is forbidden to any [other] priest after the death of her husband; as she made herself into a 'piece of forbidden matter.' And if she was trusted by him or the witness was trusted, behold this one should [divorce] her in any case to remove the doubt. And our teachers, God should keep them, instructed us (see Teshuvot HaRashba 1268) [that the latter is] specifically when she came to say this - whether she or the witness - from amidst peace between him and her. But if she said this - whether she or the witness - from amidst a spat between him and her, we should determine the matter, [such] that he is not obliged to [divorce] her regardless. As there is [then] an assumption that she was lying, and [hence] it is not fitting to believe her in her words with one witness, but rather [only] with two fit witnesses. But nonetheless, if his opinion is very reliant upon her words or the words of the witness, it is fitting to be concerned [and not] have intercourse with her. And the rest of the many details of the commandment are in Yevamot and in Kiddushin (see Mishneh Torah, Laws of Forbidden Intercourse 18).