When Sergi Prieto founded the world's first sex doll brothel in Barcelona, he claimed it was there to service "all fantasies".
But he insists there are some requests he turns down: two of the most common are rape fantasies and those looking to have sex with dolls resembling children.
Although he admits "lots" of suppliers will make dolls shaped like children, that is not a line he is willing to cross, the MailOnline reported.
Speaking to the Daily Star, he said: "That's an ethical option for us not to provide this kind of service.
"We could do that, but we don't want to promote this kind of behaviour.
"Some customers prefer the service because they have a rape fantasy," he added.
"Obviously we don't want to promote this kind of activity."
Although Sergi says he often denies requests from these sorts of customers, business is still booming and he hopes to take his brothels worldwide.
Lumidolls offers punters half-hour sessions with one of their dolls for as little as $124 or $154 for a full hour.
The dolls, which are made from thermoplastic elastomer, come with their own personality and attributes and can be dressed up however the customer desires.
One of the most popular requests is for a schoolgirl uniform, Sergi said.
After the customer is finished the doll is thoroughly cleaned and disinfected, before being prepared for the next customer.
Lumidolls owns four of the robots, which cost a little more than $7400 each.
Initially the brothel opened on Barcelona's famous Las Ramblas, but was forced to close after protests from sex workers.
It has now moved to secretive location in the city that is only given out to paying customers.
Lumidolls is also looking for franchise owners who would be willing to take their business model around Europe, including in the UK.