You stare at the picture as you you stroke your cock. You know you're gonna cum soon. Yes, it's your older sister, and that is hot. Yes she's getting covered in the cum of at least two guys, and that's really hot.
You also know that tattoo on the guy's wrist, and that's really hot! It's your 'baby' brother, and that makes your dick throb! But it's the fact that you so wish he would do THAT to YOU that makes you whimper and spray your juice all over the desk!