When do you consider a relationship to be formal?

When do you consider a relationship to be formal?
Is it important the time you had spend with that person and interact or is more important quality rather than time or both things go hand in hand? For example some peopel date for just a few months or lets say a year, and soon they get committ and they hardly know each other or there are couples who date for a long time (no more than 6 years) and when they feel ready, they may committ or not, as they want to spend more time getting to know each other. Even if this is true: You never ever get to know the person 100% even if you are married you dont know that person to their 100% extension.

Can you know well a person in just little time in order to committ soon in time or you do need time for that? Knowing that WE ALL ARE DIFFERENT, we have different attitudes, personalities, characters, behavior, that we may or not like from the other person.

Let me put you an example and tell me what kind of relationship this is:

I have a male cousin who is now 48yrs, he has 2 kids (19 and 16). He had been separated (not legally divorced yet) for like 12 years now. The son lives with him and the daughter with her mom. The guy after separation he dated a few ladies here and there and anyway the ladies he had dated after separation never been really formal or committed. Then 6 years ago, he met a lady (12 years younger) and lets say is the longest relationship he had been with so far.

At this moment I dont know if he still dates her or he is just having fun with her even after 6 yers of supposedly being together as a couple (the term couple I doubt applies for him) At the beginning of his relationship Im sure he treated her like a girlfriend, they dated often, etc The years went by and if even if he was with her, this cousin never ever introduced her to the family or even mention he had a girlfriend, possibly because for him his relationship was not formal (even with years of still dating her).

He was still supposedly.. cont
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dating her, but he never took her into account for family get together, family local ride trips, he always attended the activities or events by himself, not even his own birthdays with the family he brought her. He also in ordinary conversations with family when he was by himself, her name was never part of a talk or even he mentioned her as him having a girlfriend. They dont live together.

The few few times this cousin brought his "girlfriend" in person was in 2 Christmas Eve dinners at his
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house, and even her being there, she was like "invisible", she was a bit of anti-social, she did not like to interact much with the rest of the family, because while the family was mingling, even the boyfriend was present mingling with the rest, she was in her`s boyfriend bedroom watching TV with the closed door.

The guy at this moment we suspect he is no longer dating her, but I was told he sees her only from time to time but he stil calls her "his girlfriend", after 6 years?
When do you consider a relationship to be formal?
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