The tensions are said to have started during Biden's time as vice president, and to have continued in his early days in the White House.
'Agents say that, whether at the vice president's residence or at his home in Delaware, Biden has a habit of swimming in his pool nude,' Kessler wrote in his book, The First Family Detail: Secret Service Agents Reveal the Hidden Lives of the Presidents.
'Female Secret Service agents find that offensive,' he noted.
Kessler also outlined the agents' frustration with Biden's constantly-changing schedule and frequent trips to his home in Wilmington, Delaware.
'He would never give agents any kind of pre-warning of what his schedule was going to be,' Kessler told DailyMail.com. 'He would just, on the spur of the moment, decide to go back to Wilmington, frequently, more than once a week. And so they could never plan their their lives. They could never set up a social occasion.'
He noted agents considered Biden duty the 'second worst assignment.' The top spot went to being on Hillary Clinton's detail.
