Cosquillarte The world's first tickle spa, Cosquillarte, in Madrid

Elena Gil admits she is an addict. "It started when I was a kid," she says. "I've just always loved the way it feels." For years, Gil, a 25-year-old occupational therapy student, sought out her vice wherever she could, even bribing her boyfriend with home-cooked meals in exchange for a few minutes of pleasure. But now that the world's first tickling spa has opened in Madrid, she has a new way to satisfy her urges.

There are no facials or hot-rock massages at Cosquillarte (the name translates both as Tickle Yourself and Tickle Art). In its two quiet treatment rooms, the urban spa offers only tickling. If that sounds more like torture than pampering, take note: the place has built a steady roster of clients, many of whom book weekly appointments, since it opened in December. (See the top 10 odd spa treatments.)

Cosquillarte is the brainchild of Isabel Aires, a public-relations specialist who is herself a tickling aficionado. "My dad used to tickle me to get me to go to sleep, so it's always relaxed me," she says. "One day I just thought, Why can't I pay someone to do this, in the same way as I can pay for a massage?" Working with two trained massage therapists, Aires came up with a treatment. "There's no school for tickling," she says. "We had to invent it ourselves."

Much like at any other day spa, the treatment takes place in a darkened room, with soothing music playing and a hint of incense tingeing the air. The client disrobes, puts on a pair of crinkly paper panties and lies facedown on the table. And then the tickling  first with fingertips drawn along the body, then a feather  begins. A 30-minute session costs €25 ($35); for an hour, the price is €45 ($60). (See a Vietnamese hotel where the spa is free.)

Mercifully for this extremely ticklish reporter, Cosquillarte does not practice the fingers-jabbing-into-your-sides type of tickling. As someone who jumps during airport patdowns, I was ready with a number of excuses for why I could not possibly sample the treatment. But in the name of research, I forced myself to get on the table. I felt myself clenching as the therapist lightly traced her fingertips down the back of my neck and toward the sensitive armpit area, the site of so much childhood torture. But then, to my amazement, I felt the tension flow out of me. Before I knew it, I was enjoying myself.

"We use a variety of strokes," explains therapist Lourdes Nieto. "If someone is super-ticklish, we'll press harder. The idea is to relax them, not stress them out."

And relaxing it is, even for the confirmed ticklephobe. Cosquillarte's clients are equally divided between men and women, ranging in age from teenagers to 70-year-olds. And according to Aires, none of them have ever left unhappy. "Sometimes a new client is a little skeptical at first," she admits. "But they end up hooked."

So hooked that Aires has received inquiries about her spa from as far away as Latin America and Russia, and has started the process of setting up franchises. She is also negotiating an agreement with a Spanish hotel chain to offer in-room treatments. And with temperatures currently reaching into the 90s in Madrid, she's working on developing a summer treatment with cold hands. (See how TIME's Joel Stein learned to relax at a spa  with his mom.)

That's the kind of idea that would make Elena Gil's boyfriend cringe. Gil's enthusiasm for Cosquillarte  she has a regular weekly appointment  has made converts of two friends and a couple of family members. But not, alas, her boyfriend. "He's glad that he no longer has to do it for me," she says. "But he would never come himself. He can't stand being tickled."

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