It had been three years since I had watched Kate have sex with another guy. I never told her what I saw, but I was certain that it was not an isolated incident. I kept my mouth shut though and we carried on like any other happily married couple. After last weekend though, I am not sure if I can keep it all together.

Kate and I are both 29, and last weekend we went to a resort about 6 hours north of where we live for her brother’s summer wedding. The resort was amazing, and it was a good chance for Kate and I to spend some quality time together. The Friday night was just a family affair, a nice dinner, everyone talking about how happy they are, all that sort of jazz. I was drinking pretty heavily though and as soon as we got home I passed out cold.

Kate looked amazing for the wedding, wearing a strapless one piece, barely covering her c-cup breasts, her long brown hair coming down past her shoulders, very sexy indeed. I could bore you with all the details of the wedding, the bride, the groom but the story doesn’t really start until the after party in our room.

There was about 20 or so there, I hardly new anyone and basically just sat on the couch and waited for everyone to leave. Kate was a social butterfly, talking and laughing with them all. Most people had changed into more relaxed clothing, since it was so hot. I was just in my shorts and a singlet. Kate was wearing a white bikini top and a sarong, most of the women were dressed the same. The party continued for most of the night, outside on the deck, overlooking the beach, some people in the pool, some in the Jacuzzi.

I have no idea what time it was when I passed out, but when I woke up all the lights were off and everyone was gone. I was pretty disorientated for the first few minutes wondering what the hell was happening. I was walking towards the bedroom when I heard the splashes outside, I walked to the sliding doors and looked outside to see Kate and some guy who I didn’t know getting out of the pool.

I thought they were coming inside but instead got into the Jacuzzi. I stood there, motionless as I watched, both of them just talking. They were both laughing, talking. Kate moved towards him and turned around, leaning back into the guy, he was rubbing her shoulders, gently massing her neck. I could see her visibly relax, leaning further back into him. I watched as his hands moved further down her shoulders, down over the front of her neck and slowly massage her boobs through her bikini top. Kate did not argue, she simply moaned and let him do it.

He squeezed her boobs lightly, pulling her top down to expose each one, gently squeezing her nipples while kissing her neck. I could see her panting. One of his hands moved over her front, down underneath the water towards her pussy, Kate bit her lip as his fingers entered her, slowly playing with her clit, pushing his fingers in and out. Kate seemed to be in heaven, her breathing getting heavier. My feet were frozen, I was rock hard as I watched Kate cum, trying hard not to scream out aloud.

Kate was almost breathless, her boobs still exposed. The guy stood up behind her and sat on the edge of the Jacuzzi. Kate turned towards him, her hands grabbing at his shorts, slowly pulling them down. I saw the look of shock on her face and mouth something to him when she saw his cock, it was huge, I would guess about 9 or 10 inches long and very thick. Much bigger and thicker than me.

The guy grabbed her head and guided her towards his cock, Kate held it with one hand and licked the head gently, licked up and down the shaft, trying to fit as much into her mouth as she could. The guy leant back and moaned as Kate kept sucking deeply, running her hands up and down the shaft as she sucked, gently playing with his balls. Kate picked up the pace, sucking deeper, faster, her hands moving up and down his shaft sucking deeply.

The guy pulled her off and stood her up, he was much taller than her and very toned. He lead her out of the Jacuzzi towards a beach couch and lay her down. I could not see as well from where I was standing but I watched the best I could as he kissed her deeply, her hands holding him into her. He leaned back, Kate’s legs wide and pushed his cock into her. I hear her moan loudly “holy fuck” as he pushed himself all the way in, holding her legs wide behind her knees. He slowly started to fuck her, pulling all the way out before pushing back in.

“Fuck that feels good,” I heard her say.

Pretty soon he was fucking her harder, balls slapping against her, her moans and screams getting louder. He placed both her legs over his shoulders, allowing himself to get deeper into her. Kate was almost screaming, just saying things like “fuck yes” “fuck that feels good” over and over again. The guy pulled out suddenly and rolled Kate over onto all fours, he pushed her head down onto the couch and entered her again in one smooth stroke, holding her hips, fucking her hard. I could hear him slapping against her, his pace getting faster. I heard Kate cum again, yelling into the cushions.

I watched as the guy tensed, cumming with a moan deep in her pussy. He fell back and collapsed beside her, Kate still on her knees, ass in the air. I could see her smiling. I moved slowly away from the door and went back to the couch. After a while I hear the door to our bedroom open and Kate walking towards me. I shut my eyes and pretended to be asleep.

“Darling, are you awake?” Kate asked me.

“What is it my love, what time is it?” I replied.

“I have no idea, about 5 or so. Listen you are going to have to sleep out here for the night.”

I was confused, “What?” was all I could say back.

“I said you are going to have to sleep out here for the night,” Kate said again.

“What do you mean, what is going on?” I said as I sat up.

“I think you know perfectly well what is going on, I will be in our room with Sam," at least now I knew his name, "And you will be out here. The door will be locked so don’t even think about disturbing us.”

I didn’t know what to think. What the hell was going on. Before I could say anything else, Kate was already walking back into the bedroom. I heard the bathroom door close and lock. There I was sitting on the couch in silence wondering if it was all a dream. I was stunned, completely stunned.

After a while I got up and walked towards the bedroom, the door was wide open and I could see the bed was empty. The bathroom door was shut and I could see the light on. I slowly crept towards it, gently giving the know a turn to see if it was locked, which it was. I stood there, not moving, hearing Kate moan, hearing Sam say something to her, hearing them fuck in the shower.

I walked out, what the hell is happening? I was lying on the couch in silence when I heard the bedroom door close and lock. I must have dozed a little, when I woke I wondered it I had dreamt everything. I slowly crept towards the bedroom door, straining to hear every little sound. I could hear sex, I could hear him slapping against Kate and her moaning. I still couldn’t believe what was happening. I turned around and went back to the couch, listening for every sound but eventually falling back to sleep.

When I woke for the final time the sun was up. I had no idea what time it was. I heard someone open the fridge and slowly turned around to see Sam walking back from the fridge naked with a bottle of water. I lay on my back again, eyes wide open, wondering how this even got this far. I could hear Kate giggling, then her moaning. Sam must have left the door open, because I could hear every sound this time. I wanted to see, I needed to see.

I got up and crept to the door, making sure they could not see me, trying to look in. Sam was on his back, Kate was between his legs, taking his big cock in her mouth. Sam was leaning back moaning each time Kate sucked up and down on his cock, licking up and down his shaft. Kate stopped, moving up until she was kneeling over his cock, slowly lowering herself down onto it with a loud moan.

Sam had his hands on her hips as Kate rocked back and forth, her hands on his chest. Kate continued to grind back and forth, screaming loudly, Sam playing with her boobs, squeezing her nipples. Kate threw her head back suddenly and came loudly, collapsing into Sam’s chest. Sam quickly rolled her over and pushed her legs out wide, fucking her hard, making her scream again. I watched as he pulled out and came on her, cumming in thick streams on her stomach and boobs.

I turned away, still not really believing it, deciding to take a walk.

When I got back Sam was gone. Kate told me that she still loved me and wanted to stay married but needed more sexually. She hoped that I would understand and allow her to have fun when she wanted. I have no idea what I am going to do.