Field trip made better SeXStoRY

As part of my major in college I needed to make a field trip to the beach from my school. It was about a 2 and 1/2 drive from the school to the beach so I dressed for comfort, sweats t-shirt and sweatshirt, nothing else. We were riding in a 15 passenger van, and I was first in line. I went right to the back seat as it extended all the way across the back. There weren't too many students on the trip and so it was one to a seat until Karen got on the bus. Karen was a year behind me and majorly cute. Long straight black hair, freckles and a really nice ass. Her chest was almost flat, pretty my A-cup and she saw that as a problem, but the fact that she never wore a bra and that her nipples were always hard turned me on. She came right to the back seat and asked if she could share. She proceeded to lay down on the seat and put her feet on my lap. She put her headphones on and closed her eyes. At one point the van jarred and she banged he head pretty hard on the side of the van, so she sat up. Soon enough we were at the site of the trip and took in the sites we were supposed to see. Our professor then explained that his graduate assistant would be driving back to school as he had a house at the beach and was going to stay there for the weekend. We loaded up and took to our seats. This time Karen put her head on my lap and laid the other way. I wadded up my jacket and used it as a pillow and put my hand on her belly. Soon almost everyone except myself and the driver were asl**p. Every time the van would jostle I would move my hand fractionally towards Karen's titties. Soon I had my hand on her right breast and I felt her nipple harden under my fingers. I squeezed it a little bit and I got a little moan from Karen. I looked up and saw the grad assistant June looking right at me. She could not see Karen's body on my lap, but she could see her waist that was right in the aisle. I moved my hand to her other tit and played with that nipple and she moaned again. She also opened her eyes and smiled. So I kept doing it she turned her head and pulled my sweatpants down. She took my semi-hard cock into her mouth and started sucking. She started slow but soon was going in rhythm. I reached down and worked my hand into the waistband of the sweatpants she was wearing. Like I she was dressed for comfort and was wearing no panties and soon I had a couple of fingers buried in her pussy and I was working on her clit with my thumb. She really liked this and came pretty quickly. When she did she let out a little squeal. I looked up and saw that the driver was watching us very intently. I started watching the mirror more and at one point June and I made eye contact. We held it for a while, so long I feared that she would crash. It became obvious that she was getting turned on my what was happening about 15 feet behind her. I enjoyed Karen's blowjob for quite a while and made her cum two or three more times before I felt my load coming. I leaned down and warned her, but she just worked a little harder. I was looking right in June's eyes om the mirror as I started to cum. It was hard but I didn't make a sound, but I definitely made an O face. June smiled at me in the mirror. Karen kept sucking and finally came up. She kissed me with a mouth full of cum, which I had never done before, it wasn't horrible and I actually like it a bit. When we stopped kissing I made eye contact with June in the mirror again and she pointed to her chin. I reached up and found a bit of cum that had dribbled out. I wiped it off and offered it to Karen, she sucked it off my finger. June seemed to like seeing that. Karen rested against me and told me how she had a lot of fun, but she had a boyfriend and that I hoped I understood that she was just killing time. I told her it was more than OK and that I had a lot of fun as well. We got back to school and unloaded. I was the last one on and June said that she wasn't looking forward to taking the van back to the dark storage lot by herself. I offered to ride down with her. We chatted for a bit and then June said that she really enjoyed the show. I thanked her and told her that it was fun to do it for her. She said that what was really exciting about it was that she knew Karen was sucking my cock, but she couldn't see it. The more we chatted the more excited I started to get. She parked the van and shut it down and stood up. I stood up and reached for her hand and led her back to the back seat. I knelt down in front of her and pulled her jeans and panties down. She then laid on the seat and proceeded to eat her pussy. She was soaked and tasted great. I worked a couple of fingers into her hole and plowed her sweet pussy. Soon she was cumming and screaming. I was afraid that someone would call security. By this time my cock was rock hard again I pulled my sweats down and lined my cock up with her pussy. I moved it up and down and lubed it up a little bit before I pushed it home. I didn't waste anytime and soon I was really fucking her pretty hard. She started to cum and screamed again. We took a minute or two to rest and she got onto her hands and knees. I fucked her doggy style and when she reached back to rub my balls I soon felt them tighten and I knew I was going to shoot my load. I told her I was going to cum and she asked me to cum in her mouth like I did with Karen. I pulled out and she flipped over to her back. I stuck my cock in her open mouth right as I started to cum. She swirled her tongue on the tip as I squirted into her mouth. She seemed to really loved it and I reached down and fingered her to orgasm one more time. She was so turned on she came really quickly. When she kissed me I found that she had swallowed my cum. We fucked several more times, mostly in my professors office after hours and we had a lot of fun together. But nothing was as exciting as that first time on the van.