How hard is it to wear a bathing suit?
Sorry, but the SS job is to protect, it is not the protectee’s responsibility to live his life how the Secret Service Agent would prefer them to.
If they were uncomfortable they should have asked for re-assignment...
Unless he was harassing them in some way, the fact he liked to skinny dip, is a non issue.
Biden’s got tons of legitimate problems, and issues, but this ain’t one of them.