I know of very few people who like Wyler's interpretation of Emily Brontë's 1847 Wuthering Heights better than Luis Buñuel's Los Abismos de Pasion. In Buñuel's 1954 Spanish film there are more action, real life characters, and humor. Perhaps what surprised me the most was when everyone in the audience exclaimed that Alejandro (Jorge Mistral) looked like a vampire when he would kiss Isabel (Lilia Prado) on the neck. It was true for that was exactly what it looked like to the audiences. This made me curious why Buñuel would want a reaction such as this when it was plain to see that Alejandro did not love Isabel in the least but was using her. I have a theory that it does relate to the vampire characteristic.
Let me try to explain with a question. Why do vampires bite people on the neck? Why not just go directly for the heart or for an easier vein in the arm or leg? There are two explanations for this. The neck gives the vampires the leverage to control the rest of the body easily, yet they have enough strength in most for that not to matter. The other reason is my real point; it is the only part of the body where the victim and predator cannot see each other's expressions. If killers cannot see their victims' reactions, then they cannot react with guilt to such. By kissing Isabel on the neck, Alejandro ensures that she cannot see that Alejandro is not being sincere and that she cannot see that she really loves him and thus fall in love with her for real.
So when the audience members react to Alejandro's neck kisses on Isabel with the word "vampire," they are not only getting the point that Alejandro does not love Isabel, but also they are seeing that he does not wish to even attempt to have such feelings himself. By being detached from those pesky feelings of love, Alejandro can continue his evil schemes of revenge guilt free.