Ask her about Sam's behavior

I couldn't help but ask her the question that had been on my mind. "How have you kept yourself from killing Sam?" I asked her, half-jokingly. Kate let out a sigh, "I don't know, John. I got really jealous when he started massaging Sarah. That's why I stripped down and asked you to massage me too." Her confession didn't come as a surprise to me. I knew Kate was possessive when it came to men. I grinned. "Yeah, I liked that. You have a beautiful body, Kate." She blushed. "Thanks, John. But am I wrong? I might as well enjoy myself. The other girls are such sluts." I chuckled. "I wouldn't call them sluts. They're just enjoying themselves too." Kate looked thoughtful for a moment before nodding. "You're right. I shouldn't judge. I'll just enjoy myself too." "That's the spirit," I said, patting her on the back. "Whatever happens, just enjoy it."

We arrived at the canteen and ordered some coffee for the group. As we waited for our order, I couldn't help but steal glances at Kate's body. She caught me a few times, and each time she smiled and turned away shyly. As we waited, Kate started talking about her past relationships. "I don't know why I always end up with assholes," she complained. "I mean, Sam is a good guy, but I just can't get over how much he was touching Sarah." I listened as she vented her frustrations. "I know it's hard, but try not to think about it too much. We're on vacation, and we should be having fun," I said, trying to change the subject. Finally, our order was ready, and we made our way back to the beach. While we were walking back, she said "I might take up your advice. But it's jealousy that drives me." I nodded in agreement, understanding where she was coming from. "You can always retaliate if Sam does something you don't approve of," I added, giving her a sly smile. She just grinned and we continued walking.

As we approached the beach, we could see Lexi in the distance, laying down and Sam giving her a massage on her back. I could see the tension in Kate's face, and I knew she was thinking about what we had just talked about. As I stood there frozen with Kate, my eyes fixated on the scene before me. As Sam was giving Lexi a massage, his erect cock was rubbing against her bare ass. Kate was in shock, unable to move or say anything. I, on the other hand, was getting turned on watching the whole thing. Just then, Sarah caught sight of us behind the bushes and gave me a look of pure ****. I knew that look all too well. It was the same look she gave me when we were fooling around earlier. But this time, she had something else in mind. Sarah approached Sam, rubbing Lexi's back and slowly making her way to Sam’s abs. I could see his muscles tensing as she touched him. Then, she reached down and started stroking his cock. It was like something out of a porn movie. Kate, who had finally found her voice, whispered to me "What the fuck is going on?" I replied, "I don't know." Sarah continued to stroke Sam, her pace quickening with each passing moment. I could tell he was close to climaxing. Suddenly, she stopped and looked up at him. "Not yet," she said with a devilish grin. Sam looked like he was about to protest, but then Sarah leaned in and kissed him deeply. His hands moved to her hips, pulling her closer to him. I could feel myself getting hard watching them.