My SO and I lived in 2 apartments right next door to each other for 15 years when I was in Dallas, and we worked together at the same place for years before that. I retired to this small town in E. Texas to take care of my parents and will be a permanent resident here. He is still in Dallas working for just "one more year".
Once he finally decides to retire, he will join me here, and I am not sure how close he will be to where I live. But, take my word for it, anywhere within the city limits is almost within walking distance. He is my best friend and has just become part of the family. I have lots of family here, and he is included in everything. Both of his parents are dead, he is an only child, never married, no children. He can enjoy my 4 grandkids as long as he wants and then can go home when he's had enough! They can be overwhelming. All he has to do is leave when he is maxed out. I don't mind. He loves it. He can have family and experience kids without living with it all of the time. I don't have to put up with his messiness. He doesn't have to live with my neatness. He is cheap and I am generous. Neither of our feelings are hurt because we have zero expectation that the other person will change, and our bank accounts are separate. We have totally accepted all of those things about each other that people hate, and we have been able to do that because we don't live together! That is the key.
During the first 7 years we were together there were a lot of fireworks (mostly the good kind) and we talked about marriage. But as the hormones settled down and we began just living life, we both decided that marriage was definitely NOT the way to go and even if we did marry, we would continue to live apart! It is not so much marriage that we are against. It is living under the same roof that we can't imagine. For us this is a successful living arrangement. At this stage in our lives, trying to have a "conventional" relationship just requires too much energy and presents challenges that we both already know we don't want to deal with. We are both extremely happy the way we are. And it goes without saying that we respect and trust each other totally. Remember, for us, it has been 17 years so something is working.
Personally I think we are on to something here. If more "mature" couples would try it, they might find that life is simpler.
Ya ask one little question and you get a book! Sorry 'bout that.
TG