College 'Three's Company'

My college girlfriend asked me to move in with her. I was happy to. Little did I know that she also had two other girlfriends living with her, Desiree and Becky. After about a month of living together we slowly started to lose our inhibitions. Walking around in our underwear, using the bathroom with the door open, showering while they used the sink, etc., but never showing any nudity because of robes or pieces of clothing. Then one night we were joking around and someone suggested we play truth or dare. It started off fun, like girls kissing girls, me kissing between Becky's boobs (bra on) and then my girlfriend dared me to pee in front of the girls. I laughed but agreed. I stood in front of them with my hands on my sweat pants and my girlfriend jumped up and pulled them down. My dick sprung out and the girls smiled like they had never seen one. With about 5 minutes of stage fright, I finally peed. They refused to let me get dressed. Then it was my turn. I dared Desiree to show me her tits. I had always wanted to see them. She didn't hesitate at all. The bra flew off and WOW... nice boobs. Then Desiree dared Becky to take her top off. Within 5 minutes they were down to their panties. I dared the girls to both lose their panties and show me their goods. Becky dropped her panties and showed her bald beaver. Then Desiree dropped hers. She had a beautifully trimmed bush, her lips slightly protruding from her slit. I could not hold back. I got a hard on. The girls all giggled. To make things worse, my girlfriend kept playing with it. Then Becky said, "I dare you to jack off for us." By then I was so close to cumming as it was. I just asked them, "Where should I shoot it?" My girlfriend said, "Desiree, I dare you to swallow his cum". With the most serious of looks, Desiree said "Ok..." I took two steps over to her and she stroked it once and I came so hard. My knees buckled and I ended up squirting a little on Becky's shoulder and once again on my girlfriend's left tit. Desiree smiled and said, "That was fun." Now it has been six months since then. We actually sit and visit with each other or even lend a helping hand masturbating. Desiree is the worst. She tells us that she has masturbated at least 7 times a day for the last three years (even under her gown at her high school graduation). I watched her at least 20 times in the last month. She can cum in less than a minute. Wow. Becky loves the dildos, vibrators and we just got her hooked on the butt-plug and Cindy (girlfriend) masturbates occasionally but she rides my dick the most. Of course the girls are sometimes there to help or swallow. I feel like such a lucky bastard.