Delon is perfect simply because he is so desirable, as the wealthy Philippe Greanleaf (Maurice Ronet), not a bad looker himself, who obviously is equally self-involved (the director keeps their shirts unbuttoned for most of the film). The bond between them, at least at first and despite their open womanizing in Rome, is clearly homoerotic; they are beautiful men who like to hang out together, even if they might never come to terms with their hidden sexuality. Instead of making love, their sexual tensions are expressed in their mockery of, and in Greanleaf’s case, abuse of, one another.
As the threesome flee to Sicily on Greanleaf’s yacht, Ripley is forced to play a sailor boy, despite his obvious lack of experience, while his benefactor goes below to have sex with Marge. But even in his now obvious position as cabin boy, Ripley further shifts positions as he becomes a voyeur to Greanleaf’s acts, perhaps even tacitly with his master’s approval. But in further tests, wherein Greanleaf forces Ripley into a tethered dingy, which while, he and Marge are below, breaks free of its mooring, it is clear he has gone too far. When the yacht turns around to search for the missing dingy, finding Ripley seriously burned by the sun (the UK title of this film was Blazing Sun), everything has shifted once more.