<P> Initially Brennan was mostly dismissive of Booth due to their opposing worldviews and work styles--which is a source of friction and banter between them . Although she refused to admit it at first, Brennan enjoyed working with him from the beginning, even after their falling out when Booth got her drunk and "fired" her, and, in Season 1, she cajoled him into launching an investigation after finding three bone fragments on a golf course so he could work with the Jeffersonian team on the case despite the fact that the FBI technically had no jurisdiction . She often unknowingly offends him on a number of occasions during the first few seasons with her tactlessness, only realizing after being gently admonished by Angela or another member of the team . She comes to admire his ability to connect with people and read behavioral cues when interrogating suspects after coming to terms with her own lack of social skills . After finding out about his abusive childhood and haunted past in the Army, she also begins to respect him as a person . Booth, who is particularly taciturn in revealing emotions or speaking about his past, begins to open up to and confide in her . Since entering a relationship with (and eventually marrying) Booth, she is shown to be extremely supportive of him, even at the expense of her friendship with Angela . Additionally, she put aside her own misgivings several times for Booth's benefit; for example, she agrees to have Christine christened into the Catholic church and referenced the Bible when trying to talk Booth into forgiving his mother . </P> <P> Brennan acquired the nickname "Bones" from Booth . She initially disliked it but comes to regard it with affection . Booth and his son Parker are the only characters in the show she permits to use it and the former rarely addresses her by her first name or "Tempe". </P> <P> In Season 2 Brennan shot and killed a person for the first time while working on a string of murders connected to serial killer Howard Epps . She was forced to pull the trigger after Epps' accomplice attacked and injured Booth with a pipe . At the end of the episode she confides in Booth of her conflicted feelings and finds comfort in the fact that Booth understood how she felt . </P> <P> The relationship between Brennan and Booth has often become strained when either partner has a significant other . For example, Booth was quite irritable when Brennan dated Agent Sully, and their relationship was also strained when Booth's brother Jared was showing an interest in Brennan . Brennan constantly needled Booth while he was dating Tessa . </P>

What season do booth and brennan sleep together