The question of whether McKay and the twins are brothers is not easily answered, as there are several factors to consider. Without more information about who McKay and the twins are, it is difficult to give a definitive answer. However, I will attempt to provide a general overview of what could potentially determine whether or not McKay and the twins are brothers.

Firstly, one factor to consider is biological relation. If McKay and the twins share the same parents, they would be considered brothers. However, even if they do not share the same biological parents, they could still be brothers if they were adopted into the same family and raised together as siblings. In this case, they would be considered adopted brothers.
Another factor to consider is cultural and social norms. In some cultures and societies, the term “brothers” may be used to refer to male friends who have a close relationship, regardless of whether or not they are biologically related. This is often seen in fraternities and other social organizations where members refer to each other as “brothers” as a sign of camaraderie and loyalty.
Furthermore, the term “twins” implies that there are two individuals who were born at the same time and who share the same biological parents. However, it is possible for there to be fraternal twins, who are born at the same time but do not share the same DNA. Fraternal twins occur when two eggs are fertilized by two different sperm. In this case, the twins would not be biologically identical and may not even look alike.
It is also possible for there to be identical twins who do not look alike. Identical twins occur when one fertilized egg splits into two embryos, resulting in two individuals who share the same DNA. However, even identical twins can have differences in their appearance due to environmental factors, such as differences in diet and lifestyle choices.
In conclusion, whether or not McKay and the twins are brothers is not a straightforward question to answer. There are several factors to consider, including biological relation, cultural and social norms, and the nature of the twins’ relationship. Without more information about who McKay and the twins are, it is difficult to give a definitive answer.