I'd long suspected that my girlfriend Amy was cheating on me, but was only able to confirm it when she slipped up and left her email open on the computer. It was a Saturday morning and she was back from the gym, and I was home earlier than expected, after getting a flat tire on my bike ride. When I came in, she was in the shower, and I saw that her mail was open, so I idly looked at the screen. A random email from a friend was open, but I saw in the index one titled "Tonight", with a guy's name in the From field. I opened it, and my jaw dropped- she was having this guy over tonight, after I left to meet friends. It was clear that my gf was in an extremely submissive position with this guy, with him telling her to be wearing a short teddy and nothing underneath when he arrives.
This clearly blew me away, seeing actual proof that she was into other guys. But it also was fascinating to me, that she could be planning this while acting totally normal towards me. From what I saw, she was hooking up with this guy, including previous times in our own apartment. I was completely hard reading this, and enticed. I heard the shower turn off, so quickly scanned what I could, seeing that Nathan was arriving at 8.
The rest of the day was normal, with Amy acting completely normal, as we had lunch with friends, went grocery shopping, walked the neighborhood. I wouldn't have thought twice about her questions about my plans that night normally, but knowing what she was planning that night I was alert. The day went on like this, and I was getting more and more curious and aroused. I was drinking beer around 4, and said to myself, fuck it, I have to find out, and hatched a plan.
I decided that I was going to find out firsthand what was going on. Amy showered again around 6, and I managed to convince her, to her objections, to go out to the store with me, on my way out to my meeting with friends. When in the store, I made an excuse that I had to call my friends about our plans, and said goodbye to her, letting her finish up. Once outside I ran home.
I knew I only had a few minutes till Amy got back, so took care of the preparations I'd worked out. I used the bathroom, took a big 2 liter bottle with me to piss in later, took a bottle of Jack Daniels, and set myself up in the closet. I was going to get my own little show, of exactly what nature I didn't know.
Sure enough, a few minutes later she came in, and from the crack I'd left in the closet door in the bedroom, heard her call my name, then walk in, pulling off the casual skirt and t-shirt she'd put on for the store. She went out of my line of sight, into her closet right next to mine, and reappeared holding lingerie, which she got into. Just as the email had ordered, she donned simply a teddy, that barely went past her ass, and nothing else. I should say that she's about 5'10" and toned to a perfect degree. She wandered out, and I heard her preparing a drink in the kitchen, what I guessed was a vodka tonic, from the sound of it.
I now had to wait, and it took probably an hour until I heard the doorbell of our apartment, and Amy walking to the door. I couldn't hear what went on, but after a minute, through the crack in the door I saw the guy I assumed was Nathan carrying her over his shoulder, ass first, her teddy up around her neck. He literlly threw her onto the bed, and pulled off the lingerie. He kicked off his shoes and his pants, and jumped on top of Amy, holding her head and pushing his cock into her mouth. After only a few seconds he stopped, and went straight for the drawer in which we keep the cuffs and ropes. He flipped her around like a toy, so her head was at the foot of the bed, and bound her spreadeagled.
This is where things got interesting. He then pulled his phone out of his pants on the floor, and called someone. He was having a friend come over. Amy starting asking what the fuck, but he put a ball gag on her and shut her up.
After only 5 minutes or so, the bell rang, and Nathan went to the door, returning with another guy. I could obviously see where this was heading, but felt no urge to do anything about it. Not that I easily could- pop out of the closet?
The friend immediately started licking Amy's pussy, which is Brazilian waxed smooth. Nathan slid her down a bit so that her head was off the foot of the bed, and shoved his cock into her mouth. He was probably 8 inches, and I could see that Amy was still learning to take it. He bent over as he fucked her mouth, twisting her nipples and alternately slapping her tits. His friend, meanwhile, was untying Amy's legs, and pulled them back, retying them so they were pulled apart and spread.
I expected them to just fuck her like a porn, but they weren't so straightforward. His friend started slapping her pussy with his open hand, eliciting cries from Amy, as Nathan ramped up the tit slapping. Eventually his friend slid his cock into Amy's pussy, and I shuddered to watch it. I'd pulled out my cock, but just out of my fly, so on the off chance I got caught, I could try to quickly shove it back in.