Scott told Access Hollywood that he had a realisation about his sexuality after many prominent people from Hollywood came out as gay.
"I was just very honest about it. I didn't want to hide it so I told my sister right away. She was really one of the first people I told," said Scott.
"(Mandy) was incredibly supportive. She knew a lot of people in the business and she knew a lot of people who were out so for her it was not a big deal at all. Being an actor and being around a lot of kids with different backgrounds it was no big deal for her," he added.