小可爱小流氓小禽兽小坏蛋
[xiăo kĕ ài xiăo liú máng xiăo qín shòu xiăo huài dàn]
It combines endearing terms ('sweetheart', 'rogue', 'bad boy') to playfully refer to someone who's cute yet mischievous or unpredictable in nature, often used between lovers with teasing intentions.