Dear Steve and Shirley, I’ve been dating a 42 year old man for a while and his sister is one of my old acquaintances from college. I don’t use the word “friend” to describe her because she’s done a lot of shady stuff lately. She introduced me to her brother and he initiated our relationship. At first, he was dating someone else and his sister made sure I knew it. She said she loves his ex-girlfriend but didn’t want her dating her brother..................................................