Here is a list of colorful Chinese phrases if he speaks Mandarin. If he speaks Cantonese you are out of luck. Some of these seem to lose something in the translation. Not for Children.

 Wo xi wang ni man man si, dan kuai dian xia di yu!    I wish you a slow death, but a quick ride to hell!Zhu tou                                               Pig headQin wode pigu                                         Kiss my assGan ni niang                                          MotherfuckerGou shi                                               Dog shitShi                                                   ShitNi shi bai chi                                        You are an idiotNi shi hun dan                                        You are a rotten eggNi shi sha gua                                        You are a foolSi lang gou                                           Dead man doggieCao ni ma                                             Fuck your motherCao!                                                  Fuck!Ta ma de!                                             Oh Shit!Shen jing bing                                        LunaticSha gua                                               Retard (lit. stupid melon)Chun zi                                               MoronWang ba dan                                           BastardChou wang ba dan                                      Lousy bastardMai bi                                                Buy pussyCao ni zu zong shi ba dai                             Fuck the 18 generations of your ancestorsHa bang                                               Suck one's dickHa wo deh bang                                        Suck my dickTian yin                                              Eat pussyGan ni ba                                             Fuck your dadGan ni lao shi                                        Fuck your teacher (for not teaching you)Chi shi!                                              Go eat shit! (Equivalent to "Fuck off!" )Diao                                                  Dick, cockJi ba                                                 Dick, cockNee yin                                               Vagina (polite)Ji bai                                                Pussy (bad insult to a man)Bo ba                                                 Huge titsToo zai zi                                            Son of a rabbitChou ba guai                                          Ugly as hellCao ni ma!                                            Fuck your mother!Langun                                                Dick (lit. man root)Ni meiyou langun                                      You have no dick!Ni juede wo hen ben ma?                               Do you think I'm an idiot?Ni shi pian zi!                                       You are a cheat!Ni xin tai hei le!                                    Your heart is black!Yanse lang                                            Male whore (lit. colored wolf)Se mi mi de ren                                       LecherousSi san ba                                             BitchNi male ge bi                                         Your mother's a cuntChou san ba                                           BitchShabi                                                 Dumb cunt (used like motherfucker)Da Shabi                                              Big dumb cuntCho yade                                              Smelly slave wenchCho ji bai                                            Smelly cuntWo cao ni ba bei zi zu zong                           Fuck eight generations of your ancestorsTzau ni Daye                                          Fuck your uncleNi ya lian zhang de gen lan bi shi de                 You have a face like a rotting cuntGun dan                                               Fuck offPi hua                                                BullshitChi shi                                               Eat shitChi wo de shi                                         Eat my shitChee jiao                                             Eat my dick (lit: eat banana)Gan ni lao ma pi gu                                   Fuck your mother's assQu di yu                                              Go to hell!Wo cao ni ye ye de sao pi yan                         Fuck your grandfather's piss stinking arseholeCao ni de xing                                        Fuck your family nameNi you piao liang de lv mao zi                        Your wife is cheating Wa Cao(ch-ao)!                                        Holy fuck!Ni shi wo de biao zv                                  You are my bitchCao ni gege                                           Fuck your older brotherCao ni didi                                           Fuck your younger brotherNide muchin shr ega da wukwei                         Your mother is a big turtle