This is very confused.
It is simply false to say that ‘a family entails children’. A married couple is legally and culturally a family, with or without children.
Further, it is simply false to suggest that gay couples don’t have kin. Everyone with living relatives has kin.
Further, the last sentence is a non sequitur. The whole cultural point of your not getting married to your girlfriend is that you are not declaring yourselves a ‘family’. So of course when you take your girlfriend to the movies you are not taking your ‘family’ to the movies.
But when my wife and I visit my in-laws overseas, I am visiting family, whether or not my wife and I have children.
These are facts that would be recognized worldwide in every human culture ... well, all except for the reality of gay families, where obtuse religious ideology gets in the way of common sense.