Nickolas is a very warm host. He welcomed us when we arrived and left, and gave us numerous recommendations of places to visit and where to eat.
His house is in Kastro, on the east of Sifnos. The village is magical by itself, and house renovated in a very nice way. The balcony + outside kitchen with view on the sea is the climax of its qualities.
We had a wonderful stay there (2 adults and 2 children ages 10 & 7) although too short, and I highly recommend