As custom had it I already had my cock out and was wanking it off for the benefit of the prefects.I have a thick cock and a fine pair of heavy balls. ... made sure not to come for a week so I was well ready for Rosie.The two female teachers brought up a basket and Rosie proceeded to strip off. And oh what a lovely sight was revealed.Rosie still had a lot of puppy fat, which I found endearing. Full tits which were firm but had a little bit of bounce to them.Surprisingly dark hips. Rosie clearly. . my tongue flicking over the nipples making it more erect and hard.. I gently cup and lips and bite the nipples and I hear her let out a moan.. which makes me even more wild … one hand over the breasts squeezing and the other being sucked … i alternate between the breasts madly sucking at the skin around the areola…circling the areola with a stiff tongue and flicking the nipples as I move my mouth over them… breathing into the breasts making her want me more..My dick is hard and full….pants. It was early May and hot. The dorm did not have air conditioning. I was wearing shorts and did not have a top on. She was wearing a modest tank top that showed off her awesome breasts and shorts that showed off her awesome legs. We were talking as we normally did and the TV was on. In the process of packing I was taking clothes out of a laundry basket. I got to a new pair of string biking stripped underwear that I had purchased. I showed them to her and said, ‘Hey I could pack wearing these’.. " He was clearly there to see me, and I was clearly okay with it. We were only pretending that this was awkward and new. Kevin was still at his girlfriend's house, and Jerry knew that our parents were out of town. There was, really, no reason to ask why he was at the house.Being his best friend's little sister, I can't say that this was a long time coming. In fact, for several years he was like a second big brother to me. He picked on me, I annoyed him... Sometimes he was friendly and sweet..