Sarah has a new boyfriend, who is perfect in every way, apart from the fact that he is extremely jealous and is always worried that Sarah is going to fall for other guys. Normally, he will get really upset if Sarah even says hello to another guy on the street. However, one day, Sarah introduces her boyfriend to a guy their age that she has known for most of her life. She tells her boyfriend how close they are, how they lived together for many years, and how they plan to see each other on a regular basis. However, her boyfriend is not worried by this, and accepts it happily. How come?
Answer
The guy is Sarah’s twin brother.
