I'm On Leave so I shouldn't be here but I really need to get this off my chest & I don't know where else to talk. Recently I found out my Mum has been talking to this guy behind my stepdad's back. I know everyones definition of what's cheating is different but to me what she's doing is cheating. Apparently this guy was her 1st love & she's always said that she would get back with him in a heartbeat (news to me). They've been talking every day on the phone & they've made plans for the future. She's even talking about leaving my stepdad to go live with this guy. My sister & I tried to tell her she was being crazy but she doesn't seem to care. She is quite prepared to leave everything she has here to go & live hundreds of miles away with a guy she has seen ONCE in the past 20 years. Today was the first time I'd seen my Mum since I found out. I tried explaining that what she was doing was unfair & she was not the same person that she was when she was 16. And I guess this guy would have changed a fair bit in 20 years too. It all fell on deaf ears, I was told I didn't understand & she's right I don't. The whole time I was with her today she was like a lovesick teenager, texting him constantly & at one point he phoned her when we were shopping in Tesco! I was so angry that she answered it, even angrier when she mentioned my name to him, I don't want him knowing anything about me. My Mum & I don't have the best relationship but she's my Mum & I want her to be happy. But at the same time I care a great deal for my Stepdad & I want him to be happy too. I feel like as well as my Mum betraying my Stepdad, I am too. I see my Stepdad more than my Mum as we work together so in a way I am closer to him. In 5 weeks we are going on holiday together (me, my partner, My Mum & stepdad). Mum said she'll talk to him after that. But I can't do it. I can't go on holiday knowing what she's planning. I don't even know if I can face going to work. Because everytime I see him I just want to cry. He's had such a crap year already & now this is going to happen to him. She said when she goes she'll leave him the house as long as my brother can stay in it as well. This makes me think that she doesn't really have a clue. She thinks that because they get on ok they'll be able to live together. Maybe they can do that but it doesn't seem very realistic. I feel like such a bad person for thinking so badly of my Mum but at the same time I am so angry at the position she's left me in. I don't know what to do at all. Everytime I think about it I feel sick. Am I being unreasonable? Should I just let her get on with it?