Breeding the Babysitter. Babysitter Sex, #2

After having had his first virgin; their 18 year old babysitter virgin, Sian, Carl decides he wants to knock her up and his wife Leanne once again helps him in his naughty endeavour. After thoroughly breaking Sian in, Carl had taken her two more times, with his wife's permission. The first time was in his marital bed and the second time in her own bedroom in her parents' house. He wryly remembered humping her so hard all of her teddies fell on the floor and then slipping out quietly when her mum came home early.
He pushed the thought of her lithe and lovely body to the back of his mind as he focused on what his wife was saying. "Don't forget we're entertaining tonight. Marianne and Shamus are coming to dinner." Marianne was Leanne's old school friend that she hadn't seen for years; now married and heavily pregnant by all accounts. This didn't promise to be an exciting evening. Carl could not have been more wrong.
When Leanne's red headed friend turned up with her big round belly and swollen tits he found himself completely captivated by her. She was a beautiful woman regardless but there was something about her pregnancy that made her completely irresistible. Nonetheless, Leanne had made it clear that she was off limits; Marianne was definitely not a swinger. By the time the couple had left, Carl had a raging hard on that he was barely able to disguise.
As the front door closed behind them, he bent his wife over the sofa and ripped off her panties...