看他们甜蜜我就想咬人
[kàn tā men tián mì wŏ jiù xiăng yăo rén]
'看他们甜蜜我就想咬人'means 'when I see them being sweet, I just want to bite people'. It depicts envy in a cute way. In fact, they only make such comments out of fondness or teasing, instead of genuine malice or anger.