如今，不正当男女关系引发的刑事案件日益增多，作为一种被害人过错情形，不正当男女关系可能会对量刑产生一定影响。由于被害人过错的立法规定较为笼统，实践中对于此情形对量刑产生的影响存在不同理解，致使实践中出现量刑不统一的问题。本文梳理了被害人过错的理论及相关规定，以不正当男女关系引发的刑事案件为例，阐释该情形影响量刑的正当性，发现司法实践中存在的问题，并提出完善不正当男女关系作为被害人过错影响量刑适用的建议。

文章除引言外，共分为五部分。第一部分从理论和实践两个维度，对被害人、被害人过错的概念进行了梳理，明确了被害人过错在法律规定和司法实践中对量刑会产生实际影响。发现实践中存在认定标准模糊、相关文件位阶较低以及减刑幅度不明确的问题。

在第二部分中，首先采用文义解释的方法，对不正当男女关系进行了界定。随后，结合司法实践中的具体案例，对不正当男女关系进行分类，划分为影响婚姻关系、影响同居关系、影响恋爱关系等多种情形，全面揭示了不同的表现形式认定被害人过错的情况。

第三部分主要分析了不正当男女关系作为被害人过错情形对量刑产生影响的正当性。分别从主观方面、客观方面、关联性、过错程度四个方面论证了不正当男女关系成立被害人过错情形的条件。分析了古代与当代的刑事立法，同时结合心理学、刑法理论，进一步论证了将不正当男女关系认定为被害人过错情形的合理性，并明确指出这与被害人过错设立的初衷相符合。

第四部分通过对45个判决书的梳理，按照涉及罪名、认定被害人过错情况及说理进行了分析，发现存在认定标准的不明确、适用减刑规范的不清晰以及说理论证不充分的问题。

第五部分从完善建议的角度出发，提出了相应的建议。一是在宏观层面上，要发挥宽严相济刑事政策的指导作用，并在刑法总则中明确规定被害人过错，为司法实践提供依据；二是在微观层面，则需要辅以详细的司法解释。根据不正当男女关系的不同情形，构建了相应的认定和量刑规则，以期为其他罪名中被害人过错制度的建设提供参考，确保被害人过错司法适用的合理性和科学性。

Nowadays, there is an increasing number of criminal cases arising from illicit relationships between men and women, which may have an impact on sentencing as a victim's fault situation. As the legislative provisions on victim's fault are more general, there are different understandings of the impact of this situation on sentencing in practice, resulting in the problem of inconsistent sentencing in practice. This paper combs through the theory of victim's fault and related regulations, takes the criminal case caused by improper male-female relationship as an example, explains the legitimacy of the situation affecting the sentencing, discovers the problems existing in the judicial practice, and puts forward the suggestion of perfecting the application of improper male-female relationship as the victim's fault affecting the sentencing.

In addition to the introduction, the article is divided into five parts. The first part combs the concept of victim and victim's fault from two dimensions of theory and practice, and makes clear that victim's fault will have a practical impact on sentencing in legal provisions and judicial practice. It is found that there are many problems in practice: fuzzy identification standard, low rank of relevant documents and unclear commutation range.

In the second part, the definition of illicit male-female relationship is firstly adopted by the method of textual interpretation. Subsequently, in conjunction with  cases in judicial practice, it categorizes illicit male-female relationships into  affecting marital relationships, cohabitation relationships and romantic relationships so as to fully reveal the different forms of manifestation and the results of the determination.

The third part analyzes the legitimacy of the impact of illicit relationships on sentencing as a victim's fault situation. This part argues the conditions under which an illicit relationship between a man and a woman can be established as a victim's fault situation from four aspects, subjective aspect, objective aspect, relevance, and degree of fault. It also analyzes ancient and contemporary criminal legislation, in conjunction with psychological and criminal law theories, further demonstrates the reasonableness of identifying illicit male-female relationships as a case of victim's fault, and makes it clear that this is consistent with the original intent of the establishment of victim's fault.

The fourth part analyzes the 45 judgements according to the crimes, the victim's fault and the reasoning, and finds that there is a lack of clarity in the criteria for the determination, a lack of clarity in the application of the norms for the reduction of the sentence, and a lack of sufficient evidence for the reasoning.

The fifth part sets out the recommendations from the perspective of refining them. Firstly, at the macro level, it is necessary to play a guiding role in the criminal policy of mutual leniency and severity, and to clearly stipulate victim's fault in the general provisions of the Criminal Law, so as to provide a basis for judicial practice. Secondly, at the micro level, it needs to be supplemented by detailed judicial interpretations. According to the different circumstances of improper male-female relationships, the corresponding rules of identification and sentencing have been constructed, with a view to providing a reference for the construction of the victim's fault system in other crimes and ensuring the rationality and scientificity of the judicial application of victim's fault.