This time was pure luck, I didn't my sister was going to be there. I decided to visit my mother for the weekend, I didn't seen her for about 6 months, and my sister for more than a year. The reason was that the last time I've seen my sister we got really drunk and we had sex. I liked it and I'm sure she did too, but my sister started to avoid me. I guess our mother felt something was wrong between us but so she decided to invite us both without knowing the other would also be there. When my sister saw me, I thought she would leave or something, but no she took it very well and my surprise was when she came to my bedroom late at night while our mother was sleeping in the next room.