Are you saying that Grace and Rainier didn't live together either. I had heard that Albert and Charlene didn't.
I was more referring to that Rainier didn't marry Grace because he fell head over heals in love with her. It was more: What can she bring to the principality? Fame, money and status. Grace lifted the then dodgy principality up to new heights.
Rainier already had a woman he loved, an actress, whom he couldn't marry because she was divorced so he had to find someone who hadn't been married before.
When Albert hung out with Charlene it was more: How can we improve the playboy image of the prince? Oh, yeah, get him a steady "girlfriend" like the ones George Cluny had! But who would be willing to pose as his steady girlfriend and be ready to face humiliation in the press as they write about his other women? Oh, someone who wants the gold bad enough!
And just for the record, he treated her nicely in the beginning and it looked like a mutual infatuation. But that changed after the first revelation of other women in a very public humiliation for Charlene.
Then after she managed to hang in there for many years and Albert was getting old, they decided that he might as well marry her. It certainly wasn't love. Which is why when Albert was asked: "Is this the love of your life?" He was all, "oh, duh, I don't know."
It may not have been the Olympic gold for Charlene, but she won a gold tiara instead.
Nobody liked her. She was crash, cheap, smoking and when she was with Albert she looked at the camera with a "look what I've got" look on her face. Gradually she changed her face to look like Grace, got bigger boobs and now people are praising her for her beauty. She can sit there in her ivory tower all she likes, but there will always be people who know the truth. And the truth has a way of coming out in the end.