不会唱忐忑不想翻白眼
[bù huì chàng tăn tè bù xiăng fān bái yăn]
'忐忑(tǎntè)' refers to the feeling of nervousness. In this netname, it may mean he can't sing when he's too nervous and will not show impatience by rolling eyes. It's used here showing that this user would be sincere when singing instead of pretending to do so.