So my girlfriend Kaylee lives with me in my house most of the time, but recently this new couple named Jack and Angelina moved in next door. They are in their late 20s, and they are very artsy and expressive, and admittedly, very good looking.
They introduced themselves to us, and they were friendly so we hit it off. They are an open couple, and have always subtly hinted at us all getting intimate. Angelina is always touchy with me, and very invested in my life, but I've always ignored her advances. However, Jack also likes to flirt with my girlfriend, and as much as I try to ignore Angelinas advances, my girlfriend doesn't seem to try as hard to reject Jack. She often lets him touch her, she laughs at all his jokes, loves to hear him play guitar ect, and it's put me off. I tried to cut contact with them a bit, but things only got worse.
This week on Thursday when I got home from work, I noticed my girlfriend was a bit off. She was in a really good mood, and was wearing a full face of makeup and red lipstick, however it was all messed up. The lipstick was faded and rubbed all around her cheeks, mouth, and a bit even on her nose. When I asked her about it she got flustered, and said she was just experimenting with new makeup, and didn't notice it rubbed off. After I went upstairs to take a shower, I noticed she also soaked her panties in the sink for some reason. I started to suspect the worst after that.
The next day I went to work, and I came home. When I walked in the door, all the lights were off, but I immediately noticed some girls clothes on the floor that I didn't recognize. What I heard next stunned me, there was moaning, coming from upstairs. I walked up there to my bedroom and opened the door.
I immediately saw that Jack was mounting my girlfriend in my bed in missionary position. I was standing directly behind them, so I saw her arms wrapped around his back, and they weren't covered up, so I got a view of his balls slapping on my girlfriends ass as he pumped in and out of her. I walked to the side of them so they would notice me, and so I could get a better look if he was wearing a condom. They were in a deep kiss when she saw me out of the corner of her eye, and got shocked. She looked away in shame, and just started apologizing to me. Even though she was apologizing and trying to speak, Jack never let up, and kept kissing her neck, and thrusting in and out. She was trying to speak, but as he kept thrusting, she just started trying to hide her moans.
I looked down at his penis, and sure enough, he wasn't wearing protection that I could see. I found myself staring at him, trying to see how big he was, and comparing myself to him, but as I was, Angelina came up to me and started to apologize, and pulled me out of the room. She started trying to comfort me, saying that it's not my fault, and no feelings are involved. Seeing my shock, she started saying it's okay, and telling me to take deep breaths as she hugged me, despite her only wearing a bra and panties.
I wasn't sure what to do, cause I felt like I was getting serious signals from Angelina that she wanted to fuck, but I just couldn't get the image out of my head that this was happening, and furthermore, they never even stopped, in fact, the moaning picked back up, and I could hear it all. This went on for a couple minutes, as I was just standing there talking to Angelina, I started to hear Jacks moaning pick up.
Something about me pushed my back into the room as it was happening, and just as I walked in, I saw his body tense up as he released. He had pushed himself all the way in to her, and she wrapped her legs around him, letting him cum inside. I saw his balls tighten and his dick flex as he pumped all of himself in to my girl. They must've not known I was watching cause after he came they started kissing and she was hugging him and running her hands through his hair.
This intimacy was just too much for me and I immediately left. I drove off to, and texted my girlfriend to leave my house. I came home later and they were gone. I washed the sheets, and removed any trace of what happened.
Since it happened, my girlfriend has been texting me profusely apologizing for what happened, and trying to get me to let her back in. Angelina has been blowing up my phone trying to comfort me and asking to talk to me and even Jack as texted to apologize about what happened. I have only responded a few times but generally I'm just trying to keep my distance, because the whole thing was so weird to me, and I'm not sure what to do.