The next few days were really busy with the assignments we were all cramming to finish by the end of semester. Cassie, Tayla and I would all get home in the evening and unwind with dinner and a wine or two. We talked a lot about the way things were between us and the fun we were all having. Neith Cassie or Tayla felt any particular urge to be monogamous and be claimed as a girlfriend, though they were adamant that promiscuity carried its risks, but we were safe due to all of us having a considerable dry spell before we all started to fool around. I said I would ask Mark about his own history before he made another appearance. Tayla was quite open about Mark in the bedroom. She explained that his cock wasn't as big as mine, but it was a gusher when he came. Cassie said that I was a heavy cummer too, so that must quite an accomplishment of Mark's orgasm.
When I caught up with Mark, we were both handing in our final assignments so we met up for a coffee afterwards. Mark was flabbergasted with how beautiful and sexy the two girls were, and how they flaunted themselves around the apartment. He was starting to give me the impression that he was infatuated with Tayla, so knowing that Tayla wasn't ready to commit, I pointed out that out to him. He seemed genuinely sad, like he had been turned down. I comforted him by saying that it wasn't a bad thing, in fact, it opened up some possibilities in that Cassie might be open to sharing. He chirped up at that and again checked that he wasn't stepping on any toes. I assured him again that it was all up to the girls. I then enquired about his history, and he ashamedly admitted that he had had only one prior girlfriend, and that was a couple of years ago.
I invited him around that night to celebrate the end of the semester. The girls were excited and Cassie talked openly about 'trying him out'. They both wore their revealing best and teased me all afternoon till my hard-on ached and my balls were tingling in anticipation. I decided to go and have a shower to cool off. When I had toweled myself off and gone to my bedroom to get dressed, I could hear Marks voice through the wall. I continued to sort myself out, and when I finally went to leave my room I paused as I opened the door.
From my bedroom door, I could see into the kitchen. Standing in the kitchen were Cassie, Tayla and Mark having a laugh and talking. Cassie was preparing some snacks so had her back to Mark, but was turning intermittently to talk and flirt. As her torso twisted, her short strappy crop top would slip bringing her side breast and areola into view, with her nipple just catching on the material. Mark was alert to the sight and shifted awkwardly to hide his erection. Tayla was leaning in close to Mark as she stole the odd scrap from the snacks Cassie was making. She was using the opportunity to press her tits against Mark. Whenever Cassie turned back to the snacks, Tayla would rub her hand over Mark's tenting crotch.
Watching through my ajar door, I could see the heat building between the three of them. Mark's hips were grinding into Tayla's hand. Cassie was starting to wrap up the snacks, but was well aware of Mark's hard on, and sprung into action. She started to put the dirty dishes into the dishwasher. She did this slowly, just a couple of pieces at a time. She would bend, without bending her knees, and carefully place them into the dishwasher. Her short denim skirt lifted and exposed her smooth clamshell pussy for extended periods as she fussed over stacking the dishes. I could visibly see her pussy glistening, and after a few repeats of flashing Mark, her wetness meant her pussy lips no longer stayed tightly together. Her pussy parted, exposing the bright pink inner lips. She continued to slowly do her chore.
Mark's dick must have been rock hard. Tayla continued to rub it as Mark's face started to lose composure and lust fully took hold. As Cassie was nearly finished, Tayla sidled up behind him and reached around and unzipped his pants and his cock sprung out. She stroked it and kept Mark facing Cassie, who was bent over and looked back to see what had caused Mark's sudden intake of breath. She smiled and spread her legs, giving her pussy all the encouragement it needed to fully open. Tayla then guided his cock, holding it firmly at its base, towards Cassie's soaking pussy. His cock slowly entered Cassie and she let out a low groan of pleasure. Tayla was controlling the pace, and would let Mark thrust quickly. On the outward stroke, she would rub his cock up and down Cassie's slit and make sure it rubbed against her clitoris. Tayla was expertly teasing both of them.