Warming up my girlfriend without her permission

After knowing the lust by seeing her well, I would kill with pleasure because my girlfriend was getting slutty with my friend. I had already accepted it and liked that she was a slut. But she didn't know anything about my thoughts yet, nor did she know what I had done. It was like this that weeks passed and an idea occurred to me. My fantasy was for a masseur to touch her and make her hot and horny. I wasn't satisfied with just it being a fantasy so I came up with an idea. I searched for a masseur on the internet and talked to him, but he was one of those casual sex pages and paid ones. I told him that I would bring my wife to have massages and that little by little she would get over the line to warm her up. He said everything was okay and it would stay between us. My wife's neck was slowly getting touched and she would say oh, massage me because I have contractures. I told her I felt knots and it would be good if she went to a masseur, an idea that I took positively. A few days later, I told her to reserve a turn for her and she happily did so. I thought about waiting outside but the guy said come in and take a seat, We entered and there was a bench where I sat, a massage table and behind it a dressing room. She asked him to stay in his underwear and lie down on the massage table. While the masseuse waited, she took off her clothes behind the dressing room. The very daughter of a slut came out with a tremendous black thong that I had bought recently and her matching bra. The masseur looked at me half-rolling his eyes as if saying 'you've got a tremendous slut' to me my heart stopped, having her in a thong right in front of someone else was very strong.Real photo of the thong she had. She sat with her tiny ass facing upwards, mouth downwards, looking at the opposite side where I was sitting, the guy covered her booty and unhooked her bra to pour oil on her and start massaging her back. Everything was normal until he started massaging her legs from the ankles up, slowly getting closer to her butt. Then he started massaging between her legs, stayed there for a bit, and eventually moved to the beginning of her buttocks with his thumbs, poured some oil and it looked like it was dripping between her buttocks. He started inserting his thumbs into that area little by little, she wasn't saying anything, tremendous slut, I couldn't see her face because I was looking at the opposite side from hers but I'm sure she was already wet. At that moment, I saw the masseur had a huge bulge standing up, and what does this slut's son do? He asks him to be discreet, gets up to her face level, and stretches to massage the other side of her back, going down almost to her tits. I was getting ready to go jerk off in the bathroom because his bulge was coming back while he started touching her on the side of her tits, I almost came from just seeing it, didn't see what she did, would have loved to see her face there. The session ended at home, we got there and immediately threw her onto the couch without waiting, took off her thong and started fucking her, when we finished she went to the bathroom and I saw that her entire thong was wet from the masseur's return, I was hot all week but I think it was just because of that moment of having sex with her, realizing now that it heats me up, what a slut