Tiana Blow is my sister and she's been cheating on me with my boyfriend's dad Clarke Kent for months. I had no idea – until recently. One day I was looking at my boyfriend's phone and saw a few text messages from her. I was shocked. I confronted them both and they admitted to their affair. I was devastated and hurt. I couldn't believe my sister could do this to me. She knew how much I loved my boyfriend and yet she still chose to cheat with his dad. She had no regard for our relationship or the consequences of her actions. I'm still trying to figure out how to move on from this and forgive her. It's hard to accept that my sister would do something like this, but I'm sure it's a lesson I'll carry with me for the rest of my life.