“Morgaine blinked, trying to collect herself.  a young man, slender and
dark-haired, with dark eyes; something familiar about him, but she could not quite remember . . .”  (556)

 Could the “something familiar” be that he looks like Lancelot?  Who knows?
Morgaine falls in love with Accolon, and seems to think very little of carrying out an affair with him while married to his father, King Uriens.

 Bradley, Marion Zimmer. The Mists of Avalon.  Alfred A. Knopf, 1982.