Dating yourself. With links to sources for these points for why that's a bad idea.
[- Never Leaving Your Comfort Zone Becomes The Norm
- You Are The Enabler To Each Other’s Faults]1
- You will never learn anything new
[- You'll fight all the time or not at all
- Rivals don't always make the best partners]2
The point of "You are an enabler to each other's faults" is actually very relevant, given that in the comments you say: "Clones suffer from clinic depression by many factors." While they may come from different environments, their genetic similarity will mean that they likely react to depression in the same way--which might mean that they harmful to each other rather than helpful. Yes, they will be able to empathize with their own clone, but when it comes to depression, empathy is not always the best medicine. This will depend on the individual, certainly, but may lead to double suicides if they are both depressed at the same time--who knows!
This really depends on what level of cloning you are talking about. Do they have the same MIND? Were they raised separately? Do they compete with each other professionally because they have the same skill-set or because they, like twins just gravitate towards the same things?
How much does their life influence their personalities? How many sets of clones are there? Would they work to differentiate themselves from their EXACT copies?
Say that there's a Fred clone (female version Fredricka). How many Freds are out there? What kind of society do they form and where do they find work? How do they interact and what do they do to differentiate themselves from each other? Would it be like Orphan Black except that they know about each other? You must first understand the society you are building before you can even get into specific personal relationships.
EDIT: According to new info from the poster of this question, there's only 4 clones of the same gender in each city, and only 1 per sector in the very large city.
With this in mind--got to say, that changes everything if people are FORCED to ONLY marry those, and that's your only option. That's very dystopia indeed. Since you were asking about "dating yourself" I assume that this is the case. This huge factor would make relationships more like...an arranged marriage than say, anything resembling a standard Western-style dating situation. Otherwise, with relationship options THAT limited, I would think a great many people would choose NOT to marry, if, indeed, their only options were no marriage or marrying a clone.
If the people can marry whomever they like, they will not always marry their opposite sex clone, but they may contact them in order to reproduce. There may be a disconnect between romantic relationships and reproductive ones. I can also see people living communally to raise children, possibly. I think there could be all kinds of arrangements and configurations of households, if there is any kind of freedom in this society.
Also, it's actually scientifically impossible to have a male version of a female clone. You may have solved the many problems created by this, but you know, it's worth examining closely as you handwave...