PIPPA Middleton looked red hot – and in love – as she left a charity boxing bash in London. The Duchess of Cambridge’s sister, wearing a plunging satin gown with Wilbur and Gussie gold clutch, arrived on her own at the annual Boodles Boxing Ball at the Park Plaza Hotel in Westminster. But the 28-year-old looked starry eyed as she headed home with her on-off boyfriend Alex Loudon. The couple, dating for three years, are said to be moving in together after pals revealed Pippa has been spending more time at the London home of Alex, a professional cricketer turned City broker. The 850 guests at Saturday’s ball, which raised £100,000 for charity, also included princesses Beatrice and Eugenie plus Prince Harry’s former girlfriend Chelsy Davy and Prince William’s ex, Jecca Craig.Jecca and Spice Girl Geri Halliwell, like Pippa, wore floor-length red dresses with low-cut necklines. Tables cost £1,950 and part of the proceeds will go to the Starlight Children’s Foundation, which provides entertainment for seriously ill children. James Amos, director of jewellery brand Boodles, said: “The fourth Boodles Ball was the biggest success yet. The atmosphere was electric.”The Lt Dougie Dalzell MC Memorial Trust, which was set up in memory of a British soldier killed in Afghanistan, also benefits from the evening.