This happened while I was at uni, my bf was at another uni and we only hooked up on the weekends. I had a small student apartment in the inner suburbs in an area with lots of other apartments, mostly other students. I looked up from my studying one night to notice a naked guy in an opposite flat and then a girl also naked both kissing and touching. I turned off my room light and moved closer to the window so that I could watch unimpeded. She disappeared for a few minutes, obviously sucking him and went out of sight until they both moved onto a bed when I got a look at them both. I got a glimpse of a large cock but it soon disappeared inside her as she mounted him on top. By this time my hand was inside my trackie pants as I masturbated to their pounding and when they both came I climaxed seconds later. There was a repeat several nights later when I witnessed them 69 and then she sucked him off. They moved to another room after that and I didn't get to see the finale. My bf stays over on the weekend and after a Saturday night out with friends came back to fuck and sleep. Without telling him about my voyeuristic activities during the week I left the blinds opened, dimmed the lights a little, and hoped that the couple opposite may get to watch. I had no idea whether they could see or not but I was extra horny and excited at the possibility. So we fucked for about 45 minutes, I tried to keep it going longer but my bf ran out of puff and even trying to suck his dick hard he was ready to sleep. We repeated the performance the next night, still with no idea if the couple opposite had seen anything and if so, did they enjoy? On the Monday night, much to my delight, I saw them again, clothes on, so I switched my light off to watch. Thirty minutes later they were groping each other but then stopped as another guy appeared. Both guys then started undressing the chick, one had has face on her pussy, the other was sucking one of her nipples, WOW, a MFM is happening. I couldn't take my eyes off them, the guys got naked and there were hands and mouths everywhere. She was sucking one cock and the guest guy with a noticeably thick cock was fucking her. By now I was naked myself and masturbating. The session lasted several hours during which I lost count of my orgasms. They had some coffee and their guest departed but the couple still managed to have one more fuck before turing out the lights. Several mornings later I was having a coffee at the light cafe below the apartment block and there was the guy who I had been watching. I felt embarrassed and excited at the same time and wondered if he/they had witnessed my session with my bf. He came and sat at my table and looked an even better spunk up close, albeit with his clothes on! He didn't mess around: "I saw you the other night, no doubt you have been watching us". Um, ah, blushing a bit, "yes!". "Did you like what you saw", he said with a smile. "You bet", I responded. "Well you must come over and join us, perhaps on Thursday night?". We chatted further and I agreed to pay them a visit. They are Nick and Sam(antha) and their friend Johno may or may not turn up too. I had real trouble concentrating on my studies as the night approached. I had no idea where this was going to lead, was she bi? I had had some fem experiences and at that time I was probably bi-curious as they say in the ads. Anyway that didn't matter much, I showered and climbed into my sexiest outfit with no panties or bra and headed to the next apartment block. The door was opened by Sam who was dressed a bit more casually but looking very sexy. She kissed me on the lips and the first electric current shot thru me, we moved to their lounge room where Nick passed me a glass of champagne. Now I was already super horny but champagne makes me extra super horny and this plus the anticipation had me very wet. Without any panties on I could feel my wetness running down my thighs. Nick and Sam were sitting opposite and I could see her pussy when she opened her legs, it was time to reposition. They left a space and I moved between them, Sam ran her hand up my leg and said, "fuck, you are sooo wet". Well how could I be otherwise I thought. I opened Nick's pants and released a very respectable cut cock with a large head that I could just get my hand around. Got it into my mouth though as I held his shaved balls and teased the head and shaft with my tongue. Sam was now on the floor, my skirt was up and her head was in my pussy, her tongue flicking my swollen clit and slurping my pussy lips. I was desperate to fuck and sensing this we dropped our clothes and moved to their bedroom. He jumped on top, my fav position because I can control where the cock is inside me, and also he doesn't have much control. To my surprise, Sam placed her pussy over my face so that I could get a taste of her. She had a neat pussy with a managed bush and was soaked, I could hardly breath. I felt Nick cum into me, I wasn't quiet ready having been distracted by Sam's yummy pussy. He did produce a large amount of sperm though and I could feel his cocking throbbing inside me as the last drops were expelled. Bugger I wanted to come with his cock inside me! Sam and I started kissing and touching and we were fingering each other, it felt so good. She was good at getting 2 fingers to massage my G spot that sends me crazy. Then the door bell rang. Bugger. Nick put on a gown and went for the door, voila, it was their friend Johno. His clothes were off in record time, nice abs, smaller cock than Nick but thick and nice hanging balls. I rubbed his cock for him a bit but it was already rock hard with pre-cum on the head. I positioned so that he could fuck me doggy as Nick and Sam watched on, making me even the more excited. A felt a big orgasm coming on as we came together, fuck that was good. While this was happening, Sam was sucking Nick to hardness and we fucked for three more blissful hours. I changed my habits and walked naked in my apartment at night so that they could see me, and I fucked my bf so they could see us. They frequently put on a show and occasionally Johno would turn up as an extra. We did get together 6-7 times that year until I graduated and moved out. I still have their email and facebook details though...