One Hollywood starlet, not so lucky in love on the Riviera. Jessica Simpson was at an exclusive party on a private yacht after the Vanity Fair party at the Hotel Du Cap Saturday night, but she wasn't fitting in with fellow guests. The part-time girlfriend of John Mayer "spent the whole night following Leonardo DiCaprio around like a lost puppy," said our source. "He just seemed freaked out and kind of ignored her." Simpson's rep could not be reached.