What can I do about this traffic ticket?

The other day, My sister and mom and me were driving around. They had their seatbelts on, but felt really uncomfortable because the shoulder strap was pulling on my stomach. I took the seatbelt off for a minute and then my sister stopped at red light. Next thing I know, a police officer on a motocyle is stopped right next to my sister's car. He keeps looking and staring at me, I didn't understand, and then I saw that I didn't have a seatbelt on. So I quickly put it on, and he watches me, After the green light turns, he tells my sister to pull over, and he gives me a ticket. I'm only 16, and I just took the seatbelt off for a minute. He didn't believe me, and even argued with my mother. What can I do? Thanks.