(dropping the stray dash and "Lili Charmelle" if she is the scene partner, as her name is typically not in the main title for that specific series).
or "Rocco Siffredi: Rocco's Psycho"
If the full title includes the other performer's name as written, the most accurate formatting is: -RoccoSiffredi- Lili Charmelle - Rocco-s Psycho...