So, you don't believe in objectivity?
Objectivity may or may not exist, HOWEVER, by its very definition, it is 100% inaccessible to the human mind.
If you don't, then I say it is right for me to kill you?
Moral intuition is 100% SUBJECTIVE.
If there is no objectivity, then I cannot be wrong.
You can still be factually incorrect.
I think what you mean to say is that your OPINION cannot be proven false (but it also cannot be proven true).