One of the first massages I got was by an Asian lady. Around the middle of the hour I'd paid for, she began to tentatively massage my buttocks more firmly, pull them apart and move her fingers closer and closer to my anus, sort of circling the sphincter, probably to see how I would react. I don't think I consciously presented myself to shifting my position or doing anything overtly encouraging, but she got closer and closer and asked if I liked what she was doing. I delightfully answered that I most certainly did.
She liked the answer I suppose and began extolling the health benefits of massaging this area and along the perineum, though that was a bit hard to access in my position, telling me how healthy and good for the body such massages were. I said that I agreed quite so. I was hoping she was going to insert her finger, but she stopped at that. Was she waiting for me to suggest or ask for it? I don't know as I was pretty inexperienced with massage protocols at the time.
She then had me turn over to start work on my front side. I was pretty much erect by then and she worked her way into giving me a penis massage and asked about a happy ending. I declined, not from any notions of morality, but because after orgasm I feel sad and didn't want to leave the establishment and then take a train ride home in such a condition. It was more pleasant and fun to remain in an aroused state. I don't care for post orgasm melancholy at all.
I still gave her what I imagine the same tip would have been for a happy ending, a bit over the price of the massage itself.
I went back to the same parlor a few times, but never encountered the same lady and no others, there or elsewhere, were so openly at ease or even willing to massage around and on my anus. She was the only one.