Step brother assists in arousing boyfriend with my big ass

I was feeling super horny the other day and I decided to give my boyfriend a little surprise. I took off my clothes and showed him my big ass. He was immediately aroused and started touching me. But then, my step brother walked in and I quickly covered myself up. My boyfriend was not happy about this and asked my step brother to help him get me aroused again. The step brother, being a bit of a naughty guy, agreed to help. He started kissing me and touching me, making me even more horny. My boyfriend watched all this and got even more turned on. Finally, we all got naked and started having sex. The step brother helped my boyfriend get inside me and he came inside me. It was an amazing experience for all of us.