DIFFERENCES BETWEEN MEN AND WOMEN ARE USEFUL.

When they become Husband and Wife, the qualities of woman and those of the man together bring WHOLENESS or COMPLETE well being.

If the hubby and his wife fight about the qualities he or she does not have it can completely WRECK their relationship even if it was love marriage.

What is complementary sex?

[Not complimentary!]
Every body is not by nature meticulous, neat and tidy. He is working towards being neat.
She may not be designed to put in hard work the way he does in office. Two human beings may not have the same qualities.

Symbiotic Relation
Complement (Not Compliment) वह जो काम अच्छा करती है और आप जो काम अच्छा करलेते हैं उसमे बटवारा होता है |
इस तरह दोनों मिलकर अपना अपना काम करें तो पूरा काम होता है | साथ साथ दोनों एक दुसरे के काम में हाथ बटाते भी हैं | ख़ुशी इसी से है.
[Complement -Dictionary meaning -
In many different fields, the complement of X is something that together with X makes a complete whole, something that supplies what X lacks.]

Example
If she is good at keeping the home tidy and manages home well, it is appropriate that she takes charge of it and you are free to work in field of your expertise and generate wealth. Husband and wife do not complain, but complement each other.

Woh jo acha asani se kar sakti hai usey karna chaiye. Ap jo acha aur asani se kar sakte hai woh ap ko karna hai. Ap jaisa karte hai waisa hi woh bhi kare ya woh jaise ghar ko rakhti hai waisa hi ap bhi rakhe ya jaroori nahi hota kyonki dono milkar apna chuna hua kam karte hai to ghar bhi thik thak rehta hai aur dhan bhi ata hai. Is me khushi rehti hai, pyar badta hai.

In Couple Therapy, when I interview husband and wife individually I find both love and care for each other, both are committed to each other. However, like kids they keep arguing and fighting at home. Hurting each other, their wounds bleeding. If Counseling is delayed the bickering that can cause grave marital problems

What is Opposite Sex?

Gender Dysphoria

Gender Dysphoria is where a man feels trapped in woman’s body. She wants to get back her identity as man because that is the way he feels from inside.
It is similar when she feels inside as a woman by thoughts and feelings, but being born as man has to behave and live like a man in society.
Inner feeling is opposite of outer anatomical sex.

Dictionary:
TheFreeDictionary