I spotted my girlfriend the other night and she was dressed up in the sexiest black dress, black stockings, high heels and her best lingerie. I was quite flattered she had taken so much trouble to make herself look so sexy just for me, until she told me that her fantastic outfit was not for me and she was going out to fuck one of her office colleagues. I was a bit perturbed by this and she told me it was because I have a tiny little cock that is not big enough to satisfy her - just to prove it she yanked off my trousers and underpants and started slapping my poor insulted cock around. If things weren't bad enough, I started to get hard with her rough treatment and hearing about what she was going to do with her new stud that night.