Earlier quoted context omitted.
Actually, your parent is correct: it is sexist . It makes a distinction based on sex. It is sexism. It is not, however, negative , as your parent implied.
I've never heard sexist used to just indicate a distinction by sex. Google tells me sexist means: > characterized by or showing prejudice, stereotyping, or discrimination, typically against women, on the basis of sex That sounds negative to me.
1 : prejudice or discrimination based on sex
... and "discrimination" is what the op expressed. It is a synonym for "distinction":
Discrimination: 2 : the quality or power of finely distinguishing
Discrimination is not necessarily negative - I suspect you hold many discriminating views on all number of topics be they wine, television shows, musical groups, etc. I personally hope to continue to become more and more discriminating as I learn and grow.