I'm laughing, but no one has ever asked if 'm actually happy
I am laughing though, no one else care about whether I am really happy.
或者可以这么翻译——
Although I have a smile on my face, there is no one who is caring about my true feelings.
Though I'm smiling, no one asks if I'm really happy.
I'm smiling but noone cares whether I'm truelly happy or not
Nobody actually cocncern if I am happy while laughing.