"We are at the entrance of a dance wear store. Karen goes right to town,buzzing along grabbing a number of items. Sports bras, tights, bicycleshorts,...leotards... both of us so laden she heads to the cash register.So far this isn't too bad I think. The salesgirl is cute if a bit ditzyand young."Miss... may we use the dressing room? My sissy friend here will need tocheck the sizes of some things"Shame and humiliation wash over me as the salesgirl scrutinizes me."I am afraid it is store policy. “Whatever, Rebecca.”He kissed her again, still on his elbows, stretching down to reach her lips. Her thighs lay alongside him, her calves folded back in classic Missionary position. She bore his weight with her groin, centered psychologically if not physically within her delicate vagina. Not many 15-year-old’s fucked a 17 year old brother after school today, she imagined. She loved his tongue in her mouth.“You lost to me on purpose that first day, didn’t you, Rebecca?”She scowled. “I did not!. When she got dressed she confused a pair of thick, dark hose for a pair of leggings. She didn't realize they were see through. She was giving everyone a show, having gone out commando. She had no clue, it wasn't meant to be a sexual adventure, just a trip to library. She thought it was cute that someone was flirting and she was making plans to hook with him at another time so we can do our thing. That's when she asked him to snap a pic to send me of her at the library. After he does. "Wow ... That was some nice cum!" Brad exclaimed, "much better than mine." I was not quite sure what he meant by this so I asked what he meant by cum. "Well it's what the guy on video said just as he ... Shot." With that brad got off his knees and walked out of his room and towards the bathroom, closing the door behind him. I, still recovering from cumming, looked at my semi hard cock and pulled out the rest of the cum that had collected on the head of my cock, placing it in my mouth. I have to.