I've had massages without towels at two different places. One was in the middle East, but it was at a place that had a Western clientele. They didn't use towels. I just undressed to my boxers, and the therapist (a fat, middle-aged lady) gave me my massage in my boxers. There was no 'happy ending,' but she did at one point, stand behind my head and rub her hands from my chest all the way down my abdomen. This resulted in her large breasts (under her shirt) smashing into my face for about 5 seconds. I had a full erection under my boxers the whole time. She did push on my erection, through my boxers, for about 2 seconds. I have no idea why she did this. Maybe to let me know she saw it.
The second place, I went to a few times. Actually, two places in the same shopping mall in South Korea. They don't use towels, but they do give you little thin black paper panties to wear. They really seemed to be designed for a woman, but that's what they gave me. The place that I went to about 4 times would always pull them down when they were massaging my back, so that they could massage my bare butt. But they got pulled up before I flipped over. One of the therapists told me something about the paper underwear being required by the local authorities. One of the massages there resulted in a major erection while she was working on my back. When I pulled the little underwear up, I had to pull it pretty high to cover my erect penis. I honestly didn't realize until I got up at the end that one testicle was exposed the whole time she was working on my front. I had also developed a fair amount of pre-cum, and it had leaked through the paper garment. The therapist never acted like she noticed either.
One of the therapists at the establishment in South Korea seemed to be flirting, and I think she would have liked me to request a massage in my hotel room, which, I guess, would have cost me a lot more. I don't know for sure because I never asked.