Can you ever be in an equal relationship with a man in a society where men and women are unequal?

No. Women have been cognitively programmed by a long history of patriarchy to project humanity onto men where it doesn't exist. In that regard, even if all other factors (social, economic, legal, etc) were evened out, it would not address the issue of men's inability to cognize women as Human while women see "too much" Human in them and, as a result, continue to think these are beings that one can make a meaningful and fulfilling life with. Because, frankly speaking, I think the real end goal of patriarchy is just that: tricking women into making their lives with men, which improves the lives of men.