因为爱上你那2b似地笑
[yīn wéi ài shàng nĭ nèi 2b sì dì xiào]
Loosely translated, this means 'Because loving you is as silly as my foolish smile.' It humorously captures the giddy feeling when infatuated or smitten with someone. '2B' can denote stupidity/foolishness yet here highlights carefree laughter brought about by being in love.