A randy couple were nicked as they had a steamy sex session — on the Queen’s front lawn. Crowds of astonished tourists watched as the drunken pair stripped and got down and dirty on a private grass bank at Windsor Castle, where Her Majesty was in residence. They kept at it for 20 minutes before armed Royal Protection Squad officers stepped in to take down their particulars. The pair romped in daylight beneath the castle’s Garter Tower, in full view of hotels, pubs and shops over the road. Some onlookers cheered them on while others shouted “disgusting” and called cops....