Matt was a fickle young man with his morals in the wrong place. His scheming mother saw this and took advantage of this to get rid of her husband, Matt's father.
Tiffany seduced her son and took his virginity. She then promised to continue having sex with him if she helped him get rid of her father. Matt somehow caused a car accident which took his father's life.
One night, Matt came into his mother's room and they made love. Amanda, on her way back from the bathroom, witnessed this and finally went insane, setting the house on fire and killing Matt, as well as Tiffany and Tamara.