One of my best friends (let's call her Lucy) is dating my ex (let's call him Steve). I still get on very well with Steve, and our relationship was good at the time. The problem is, Lucy hats cheating, and I know that Steve used to cheat.
Steve's ex wife Jane hates Lucy, because Jane left the marriage and moved away, leaving her kids with Steve, and now Lucy is spending a lot of time with them. Jane is always telling Lucy and Steve to split up, but Lucy thinks that, as Jane cheated on Steve, she has no right to dictate her ex husband's life.
The problem is, yes Jane did cheat on Steve, but he cheated first - with me. He was still in an intimate relationship with Jane when he started going out with me, even though he swore blind that they were in separate beds. We went out for almost 2 years before he actually split up with her properly.
So, AIBU to tell Lucy that her DP isn't quite as innocent as he makes out?