When people are happy in a relationship, they live in the here and now. If everything is fine in real life, then you just don't see the point in wasting time trying to prove to someone that you are happy with your loved one.

Happiness is simply a good relationship with your loved ones.
No one has to prove anything to anyone. People don't use each other to prove how happy, successful, and loved they are. They are together because they want to be, not because of the "marital status" check mark. But, of course, to advertise your personal life or keep it a secret is a personal matter for everyone.

Do you think I understand what it means to be truly happy?
I wish everyone to find their soulmate on this site and be truly happy in this life.