There is an increase in the display of Homosexuality in movies today. My 10 year old finds it very odd and asks questions. How do I explain the concept to him?

Tell him the truth. A 10-year-old is much smarter in today's times. Tell him that love can be between any two people irrespective of the gender. It is not funny, it is not abnormal. Our society still has difficulty accepting it but its very normal.