(available from here)
O borrowed this book from his parents last time we visited. I thought I'd share an extract with you;
Martin Martin
Western Isles, C. 1695
It was an ancient custom in the islands that a man should take a maid to his wife, and keep her the space of a year without marrying her; and if she pleased him all the while, he married her at the end of the year, and legitimated these children; but if he did not love her, he returned her to her parents, and her portion also; and if there happened to be any children, they were kept by the father: but this unreasonable custom was long brought into disuse.
Well O has had me as a trial wife for 7 years now so I reckon he is happy to keep me. We were both really surprised by this concept of the trial wife given the whole "you must not live in sin" thing.