The Mail reported that the trio attended an auction organised by celebrity manager Jonathan Shalit in aid of animal charity The Hope Sanctuary, before continuing the party at the plush Sandy Lane hotel.
Former Baywatch star Carmen has not been spotted on the trip, however. Earlier this month Simon, 53, admitted he had been on dates with the actress.
He told radio host Ryan Seacrest: "She's not my girlfriend," before adding: "We've been on some dates. She's adorable, isn't she?"