I think I have been to Arena only twice, one boy did this technique and the other not. Indeed very interesting and I would like to get more of, "undercarriage service" in old shamelessmack (long gone). Ne from Buriram, the one who did this technique around 2016.
Some places offer, here a quote from Heco Phnom Penh: Sensual Massage 60 min 28 USD, Tantra / Tantric Massage 60 min 48 USD. Any experience? Is it worth the money? There was a tantric massage years ago in Ratchada, I never went but remember reports it's underwhelming.
Google search for "hegre sensual massage" images or video, there are some erotic massage techniques out there, but in Thailand they only do the same old stuff.