Despite her many opportunities to get laid, to feel a hard cock shoving into her cunt, she resisted. Not because she didn't want to get fucked, but because she was somewhat particular about whose cock went into her cunt. Yet for some reason, this time, as she felt the throb of the hard cock on her ass, a quiver went through her, and she could feel the crotch of her panties becoming wet. The wetter they became, the better it felt to Susan. She gripped the strap hard as she swayed, and with just a slight adjustment of her ass, she made sure the cock was pressing at her asscrack. She heard a soft sigh behind her, and grinned to herself. She flexed the cheeks of her ass, and heard the sigh of pleasure again. She could turn her head and see who it was, but she didn't want to see what he looked like.

Feeling his cock throb at the crack of her ass, Susan let her imagination flow with the images of who she really wanted to fuck. It was her secret, and had been her secret for two years. She never felt guilty or ashamed of her erotic fantasies. They felt too good to cause her shame or guilt.

With a slight wiggle of her ass, she pretended it was Tommy's cock pressing against her. She closed her eyes as the image grew, and writhed her ass, flexing her ass cheeks as the cock throbbed between them. In her mind, Tommy's cock rubbed up and down her ass, so very hard and hot. She wasn't dressed, in her mind, but wearing panties. Thinking this way, she could almost feel the cock better. Whoever it was behind her was rubbing up and down, sliding his hard-on along the crack of her ass. Susan kept tightening her ass cheeks, letting them relax, then tightening them again.

The subway stopped, hut Susan stood where she was. A few people managed to get off the train, and a few more squeezed in. The man behind her was pressed tighter, and his cock seemed to slip between the cheeks of her ass, through his pants, and her dress and panties. It felt like an enormous cock, but it was difficult to tell for sure.