After a further few minutes, I got carried away with myself and accidentally knocked my hand against the door. Upon hearing this David jumped back onto the sofa covering himself and Nicole grabbed a near by pillow. I opened the door cock still in hand and said "you don't have to stop, as long as I can watch". Nicole asked "are you sure", "you're not angry". I advised I wasn't and for them to continue as they were.
I sat on the sofa at the far end from where they were now sat. I was as hard as I had ever been and removed what clothing I had left on. It was at this point David had bent Nicole over the arm of the sofa and thrusted his massive cock inside her again. Now that there was no need to hide it, Nicole let out the loudest moans I had ever heard from her. Her faces with every thrust, showing he was pleasing her in ways I never had.
They continue to fuck, David pulling Nicole's hair as she moaned his name. After a few more minutes I was beating off harder than I ever had and eventually blew my load onto my stomach. This obviously did not stop their enjoyment. Nicole looked me in the eyes and laughed. "Do you... like watching... a real man... fuck me" she said, in between the moans. This made me immediately hard again.
After another 5 minutes or so, David blew his load deep inside Nicole. No condom, no contraception. He continued to slide his cock back and forth for another minute, making sure he emptied every drop of cum inside her. As he pulled out a small load more landed on the outside of Nicole's pussy, coating it perfectly.
David stood up and put his clothes back on. "I think it's time for me to leave" he said. As he left the apartment, Nicole lay there on the sofa breathless and filled with his cum. She looked at me and asked "do you want to add more?". Without missing a beat, I stood up and approached her, as she flipped onto her back.
I rubbed my cock against her clit, coating it in the still warm cum David had left. I then slid my cock into her cum filled pussy with ease. I could feel that David had really stretched her out. I started thrusting back and forth. However, due to how amazing her used pussy felt, I only lasted a further 30-40 seconds before dumping another load inside her.
After this, we washed up and went to bed. The next morning, all I could think about was what had happened, each time becoming extremely horny. We discussed what had happened and agreed that Nicole could continue to fuck David as long as no one else knew.