The title says it all, what's the difference between 見てない and 見たことがない?
Lately, I've seen japanese people using 見てない to express that they have never seen something, eg:
この映画は見てない。
But I thought that 見てない would be used in the following fashion:
今、映画を見てなくて、晩ご飯を食べてるよ。
And how different it is from:
この映画を見たことがない。
is the usage of 見てない a set phrase or something?