my best friend has a gorgeous twin brother and we have often openly flirted as a fun thing but I do really like him. yesterday i was at their house waiting for my friend and her parents to come home and talking to her brother who was going out later, he said he needed to change and I asked as a joke if I could watch and he said "yes". we went to his room and started to make out and he got a boner and laughed and things happened and I jerked him off and he touched me and it felt great. we want to go out together but i am not sure how his sister will react - we are both 16 btw and she knows I like him