Sergio was nice and allowed us to drop off our luggage early in the day. When we came back on the evening, we checked the beds and we found bedbugs in one of the mattresses, which was also really dirty.
We told Sergio that we couldn't stay and he accepted directly to give us a entire refund.
In conclusion : the apartment was clean, the sheets were all new and the equipment well, but owners of apartments in big cities have to make sure that the beds are not infected before renting it ! This is the most important thing and it hasn't been done here...