Can't Believe I Did This

My ex and I have been broken up for a year now and I had moved on or at least I thought I did. I ended up dating someone else eventually, a very nice and sweet girl but she was a virgin and that really took some getting used to. Eventually we did have sex and it was fun but a lot of times I ended up feeling bored or unsatisfied. Some time passes and my ex just happens to tell me she's coming into town and wanted to see me on her way. We hadn't seen each other in a while so I didn't think there was much to worry about and I just wanted to see a familiar face. We spent the day together and nothing happened but as soon as nighttime came its like something took over me. I started noticing how low her shirt was, how short her shorts were, and just how much fatter her ass had gotten. She always had a fat ass and you could really feel how big it was the more you grabbed it and the harder you grabbed it. We started laying down together and next thing I knew we were right on each other and I could help myself she was so warm and soft and just ready to get fucked. I started playing with her nipples but the harder I got the more I thought "I shouldn't be doing this" but the more she touched me the, the quieter the voice got. Before I even knew she started sucking my cock and it felt like heaven. I haven't had my cock sucked and throated real sloppy in so long I couldn't control my moaning. She left such a big mess all over me and the layers of sheets and on her face. Her face stain with slobber and cum I couldn't help but fucking her. It felt so good to just fuck and fuck I forgot how good it had felt to really go at it. Her juicy ass backing up on me, her warm, wet pussy just taking every inch of my cock just felt like heaven. When I came she got on her knees and stuck out her tongue and at the moment I'm ashamed to admit but I remembered I cheated but I really didn't care.