Is a British New Wave Film, often neo noir-style involving crime, and a little of what were called Kitchen Sink Dramas, made in low budget black and white.
The two young men, daring each other to score with a woman, were very much in the mold of how the real life thrill killers Leopold and Loeb were fictionally presented in films such as Rope and Compulsion, one alpha male, one beta.
Opening credits: The characters portrayed in this film are entirely fictitious and not based on actual persons.
The song in the beat nightclub sounds like Tequila by The Champs.