kěyǐ bùzéshǒuduàn/ angolul

all's fair in love and war▼(unpleasant behavior is acceptable during love and conflict)
phrase
[UK: ˈɒlz feə(r) ɪn ˈlʌv ənd wɔː(r)] [US: ˈɒlz ˈfer ɪn ˈlʌv ænd ˈwɔːr]

the end justifies the means▼(morally wrong actions are sometimes necessary)
phrase
[UK: ðə end ˈdʒʌ.stɪ.faɪz ðə miːnz] [US: ðə ˈend ˈdʒʌ.stə.ˌfaɪz ðə ˈmiːnz]