Can't stop thinking about brother's big cock

My stepsis caught me jerking off to a porn vid in a bathroom and as she confessed later she could not think about anything but my huge cock ever since. She was kinda persistent in her attempts to seduce me and finally I gave up cuz she said she was going to college in a week and nobody would ever find out. Man, this bitch always wanted to fuck me and although I never thought about it before we had a great time saying goodbye before her departure.