I was reading a story about a high school student. He was tied to a tree and beaten by some "classmates", bullies. He was rescued during an electrical storm by aliens and had his body enhanced. He also seems to remember having sex, losing his virginity to an alien woman while under alien control. He grows much bigger overnight.
He is 18, his sister is 20 and works in childcare, dad is a drunk mill worker that is very abusive to the entire family.