Cheating on my girlfriend with my cousin

I've been dating my cousin Carolina for a few months and we stopped fucking because she doesn't want to risk getting pregnant. That was 4 months ago. I haven't masterbated in months either and I'm getting so horny all the time. I sat down, looking at my girlfriends body, so curvy and hot. I needed it so badly. "I've got errands to run, you coming?" I snapped out of it and I said "I'm fine" she smiled at me and walked away and out the door. "Bye". The second the door closed, I pulled out my phone and called Gloria, my other cousin. She answered saying "hey, what's up" "I need your body right now" "why don't you ask your girlfriend for sex?" "She doesn't want to risk getting pregnant" "how long has it been?" "6 months" "damn. On my way" she hung up and 20 minutes later, she knocked and I immediately opened the door and I grabbed her hand and took her inside. I noticed something. She's changed. She's no longer boney. She's has muscle and her ass is so much larger. I wondered if it was sag or muscle so I put my crotch on her ass and pushed in. It sprang back like a spring mattress. Damn. It was all muscle and it had some bounce to it. "Wow" "you like it?" She shaked her ass. I kissed her so violently and she did the same. I was so horny, I then went for her pussy. I ripped off her yoga pants and underwear and immediately pushed it inside. A little surprised, but then moaned. That springy ass made everything so much better. She moaned like crazy. I wasn't going slow. I had the long missing feeling. The cum was on its way then all of a sudden, the door opened and my girlfriend came in. We were both surprised and I pulled out before I cummed. She looked at us, furiously. "WHAT THE FUCK YOU DOING!" Gloria stepped forward and said "since you couldn't please your man, I had to do it for you" she stomped to me and asked me if it was because she didn't want to fuck. I nodded my head. She took a deep breath and apologized for not giving me at least a blowjob. She said she'll make it up right now. She turned to Gloria and kissed her. Gloria looked puzzled but soon fell into it. She rubbed each other with Gloria's juices and ate each other. I told them that I liked the light show but I needed something more real. They understood and walked towards me. My girlfriend went on top of me and put my dick inside. We fucked for a while and switched every 4-5 minutes. I loved it