Erotic massage parlors in Marbella are in an ambiguous twilight zone. It’s a resort so naturally there are some superb masseuses and studios but there are also whole villas being rented out and transformed into luxury bordellos with a massage intro.
Nikky’s Mass (http://nikkymass.es/) at Avenida de Manolete 11-12 has great looking girls and unusual options like a “mutual massage” with a happy ending, described as “giving the pleasure back, sharing it” with your massage therapist. Happy RelaxTime (https://www.happyrelaxtime.es/) at Camino del Ángel, Puerto Banús local 34 is also a great massage studio with stellar reviews and everything you’ll ever need to release all that stress you’ve accumulated while sunbathing on your yacht.
Villa Romana Marbella (https://www.hotelmarbellaromano.es/) on the city’s outskirts at Calle Victor O'hayon Taplero is one of those converted mansions I mentioned earlier. They promote themselves as a club for adults with a huge section dedicated to massage, but they have rooms where their guests can stay and organize various events and parties. Prices at massage salons in Marbella start at about €100 for the basic stuff but most likely you will be strongly encouraged to opt for more expensive packages.