My wife and I routinely have coffee at the Apsara coffee shop in Nha Trang and always sit at the same table. I watch the couples coming in and think I can tell which ones are married and which ones are dating.
The young, unmarried couple walk together often hand in hand. They choose the table they want together and sit and talk.
The middle aged married couple man walks far ahead of his wife totally ignoring her and when she suggests a table he pays no attention and keeps walking until he finds a table he likes, sits down and starts playing with his phone still ignoring her.
It reverses back with very old married couples. They come in, often with one assisting the other, sometimes they are both doing the assisting. It’s great to see.
Before someone gets their nose all out of joint this is not a scientific study. It is simply what I have observed five or six days a week for five years. My Vietnamese wife, my sister-in-law and mother-in-law all confirm my assessment.