You can date a Brother's daughter. But you can't have any "unlawful relations" with her!
My wife (she was my girlfriend then) and I moved in together 5 years ago. This was before I was a mason, or really, knew anything about freemasonry. Dana, being a former Jobie, the mother of a Jobie, the daughter of a long time mason, plus both of her kids have had surgery at the Shriner's Hospital (her daughter cut the ribbon at the opening ceremony of the new Shriner's Hospital Twin Cities), was very encouraging, we'll say, insistant, on me speaking to her father about masonry. He, being an old timer, of course, wouldn't bring the subject up to me, I had to ask him. So I did, and a couple of months later I was initiated. So, of course, during the 3rd degree, when a particular part about unlawful relations came up, I nearly swallowed my tongue! It kept popping back into my head the rest of the degree....What did i get myself into. Immediately afterward, I ran straight to my mentor, and, well you know....