Paul Marciano, the influential co-founder of Guess, has stepped away from his day-to-day duties on unpaid leave while the company investigates recent allegations of improper conduct made by model-actress Kate Upton. She came forward earlier this month to accuse Marciano of assaulting and harassing her when she was 18, saying that on the first day of a Guess Lingerie shoot in July 2010, he accosted and groped her.