「分裂」的心理狀態是客體關係理論中十分重視的議題，指的是嬰兒從出生以來，感知到重要他人及所處環境時好時壞，所產生一種「好壞分裂」的矛盾與衝突感。在嬰兒的認知還不足以理解重要他人為何有時生氣、有時高興的時期，會習慣將某部分的感覺與特質排拒出去（通常是壞的感覺與壞的特質），以保護自己不受外在干擾—這個排拒某部份感覺與特質的歷程，客體關係理論稱之為「分裂」。研究者在從事婚姻治療的臨床經驗中，發現「分裂」的心理狀態及整合與否，對伴侶之間的相處甚為重要；有重複性外遇的婚姻關係，更深受此心理狀態所擾。在本研究中，研究者以深度訪談一位男性外遇者所得之敘說資料，透過詮釋現象學的分析方法，與客體關係理論中與「分裂」議題相關之文本進行探討與對話，深入分析：男性外遇者如何透過婚姻關係中的外遇經驗，來整合內在的分裂性情感以及外遇關係中，具有什麼樣的分裂心理現象。研究結果發現，男性外遇者的分裂性情感包含四個面向：1.在成年親密關係中，感受到外在客體好壞的分裂；2.在外遇經驗中，感受到自體好壞的分裂；3.在外遇經驗中，體會本我與超我的排拒及衝突；4.在外遇的掙扎中，喚醒原生家庭未代謝的分裂性情感。在整合分裂性情感上，亦有四個相對應的歷程：1.從足夠好的性經驗中體驗好壞情感之整合；2.在被視為恆常客體之對象身上感受到好壞經驗的整合；3.接納配偶身上的母性形象與超我形象；4.覺察原生家庭未解議題在生活中的延續，開展內在客體關係的和解。研究者認為，外遇事件可視為內在分裂情感的行動化，在外遇後的婚姻重建實務工作上，並不能只看到被外遇者的創傷與失落，更要協助外遇者體察這種破壞婚姻的衝動來自何方；此外，「性關係的重建」也許是對婚外情治療具有關鍵力的重要元素，促使早年與原生家庭之議題浮出意識層面，得以被夫妻雙方所處理。

＂Splitting＂, as stressed in the Object Relations Theory, is a very important psychological state in human development. It refers to a sense of contradiction and conflict of ＂being split into all good or all bad＂ formed since birth through perceptions of significant others and surrounding environments, which are sometimes good and sometimes bad. When a baby does not have sufficient knowledge to understand why significant others are sometimes upset and sometimes happy, he/she would instinctively exclude some feelings and characteristics (usually bad ones) in order to protect himself/herself from external disturbances. This process of excluding some parts of feelings and characteristics is called ＂splitting＂ in the Object Relations Theory. We found from clinical experience in marriage counseling that the psychological state of ＂splitting＂ and whether the split parts can be integrated back to the self are quite important for healthy marital relationships. Couples who repeatedly have affairs are often deeply affected by the state of ＂splitting＂. This study is aimed to examine how ＂splitting＂ works in an affair and how integration of internal splitting was carried out by unfaithful husbands through their marriages. Data was collected by conducting five in-depth interviews with a man who had been unfaithful to his wife. Based on the Hermeneutic Phenomenology approach, data analysis was further performed through discussions and dialogues between the interviewee's narratives and the theoretical texts with regard to ＂splitting＂ in the Object Relations Theory. This study found that the ＂split＂ affections of unfaithful husbands consist of four layers: (a) experiencing the state of ＂splitting＂ between the good and the bad of external object in adulthood intimate relationships; (b) experiencing the good and the bad of self in the extramarital affairs; (c) experiencing the mutual exclusion and conflicts between the id and the superego during the affairs; and (d) becoming aware, while struggling with the affairs, of the unresolved ＂split＂ affections from the family of origin. In the integration of ＂split＂ affections, there are also four corresponding processes: (a) integrating the good and bad affections through the ＂good-enough＂ sexual experiences; (b) experiencing the integration of good and bad on the proposed, constant object; (c) accepting the maternal and super-ego images projected onto the partner; and (d) becoming aware of the unresolved issues from the family of origin that are carried over to the current marital relationship. It is believed that an affair can be considered as “acting out” the internal ＂split＂ affections. When rebuilding a marriage after an affair, we must work on not only healing the pain and loss of the betrayed but also help the unfaithful partner to understand where this undermining impulse came from. In addition, the ＂reconstruction of sexual relationships＂ might be an essential factor in counseling marriages involving affairs, for it enables the unresolved issues formed in the families of origin to emerge onto the consciousness where they can be worked on by the couple.