I think Chopin during sex was like a manifestation of their connection. Chopin became one of the main points of contact for the professor and Garam because in this way Garam was able to look deep into the professor and his feelings. And it's also loneliness for the professor. It looked like Garam again touched the strings of the professor's soul and pulled them out literally telling him I love you, I accept you, show me yourself. After all, at the end he wonders if he can cope with it, does he deserve to no longer look back at Eurydice and go only forward
Very complex feelings and emotions and that makes it amazing