Serena, my bisexual friend SeXStoRY

I am a married female aged 52 living on the south coast of England. I am very bisexual and having an affair with my friend Serena who is 43. My husband Rob knows I am bi and knows what I am doing with Serena. Her husband Mark does not even know she is bi. She visits me twice a week for lunch and we end up fucking and sucking each other. Rob would love to watch us having fun but Serena won't let him. I give him all the details when he gets back from work and I usually wank him off while I'm telling him what we did to each other. A couple of weeks ago we decided to all go out for a meal together. After we had eaten we were sitting having coffee when Serena and I needed to go to the ladies. When we got there we started kissing and feeling each other. Soon we had our skirts up round our waists and were playing with each others pussy through our panties. In a matter of minutes we had made each other cum and soaked our panties. We then swapped panties and joined the men. I was lovely being able to feel the dampness of Serena's cum stained panties against my pussy. When we got home I told Rob what we had done and he started licking my pussy through Serena's panties. He loved the smell of her cunt juices. Soon he made me cum in them too. I then took them off and as he held them to his nose and smelled them I sucked him off into my mouth. Last weekend we went out for a dring with Seren and Mark and Rob wore Serena's cum stained panties. He said he had a hard on all evening knowing she had worn them and cum in them.