Looking at the two completely different types of personalities as described in media.....
Morgan outgoing, social, confident, didn't upset anyone, embraced people, true gentleman.
DJK a loner, who never drank, read books by himself over soft drinks at a nearby cafe. Seems to always have a book on hand??
They could very well have struck up a conversation about books, perhaps Morgan mentioned a book he had back home. Being a nice guy, he invited DJK back to give it to him. Except DJK may have wanted more or thought there'd be more....mistaking Morgan's friendliness to be of a sexual nature.
Morgan declined him, which infuriated DJK, he went ballistic, repeatedly stabbed him. The accused could have removed the shorts & had sex with Morgan following the stabbing or masturbated over him.
As happens in some cases....they can't handle refusals or knock backs so they take what they want after they've killed the person.