没事儿似的

没事儿似的

Literally means:

as if it were nothing

Actually means:

pretend to be uninvolved or uninterested

It means that somebody looks as if he was uninvolved in something, or that he did not care about something at all. In fact he has something to do with it or cares very much about it.

看上去好像与某事没有任何关系，或者对某种情况一点儿也不在乎。实际上与某事是有关系的，或者心里很在意，只是表面上装作不关心、不在意。