Seducing my younger brother

Our father wanted to sell our grand-mother's old house but he didn't want to pay to a real estate agent so he made us an offer. If me and my brother accepted to stay there for a full month so we can show the house to possible buyers and sell the house he would pay us the amount he had to give to the real estate agency. It was a great deal, the only problem was that the house is a bit isolated and in a touristic zone for old people because of it's thermal waters. There isn't much activity besides spending the afternoons at the lake. After the first week we started to get bored and I started to flirt with my brother and things appended. At end it was all good, three weeks fucking like rabbits and we even sold the house.