Sisters dating brothers

Look, if you want to date your own sibling, that’s a problem. You must see a psychologist.
However, if you would like to date your brother’s wife’s sister, that’s okay! In the future, when you marry your brother’s wife’s sister, the family ties will become very strong. Congratulations on that!
Having said that, dating someone so close to your family also has disadvantages:
1) It’s not going to help you with your social circle. It is said that people you are very familiar with can’t help you with your career because if they can, they must have done it already. By contrast, weak links (weak ties) are much more likely to help you with your career because these people have very different resources that you probably need. A weak link can be an acquaintance that you meet at a business conference, a client that you’ve met on the Internet, your friend’s neighbor, your professor at university, your co-worker’s husband, and so on.
2) When you marry your brother’s sister’s wife, your mother-in-law and your father-in-law will also be your brother’s mother-in-law and father-in-law. Can you imagine what would happen when those in-laws pass away in the future? I’m sorry to mention this, but if they have a lot of money without a Will, that may cause a dispute in your family.