I watch porn and see how people are doing it I think this is something that two individuals are craving and there is a consensus and perfect understanding.
That 'craving' is acting, for money, and lots of money for what is typically an off the record drug habit. There is no lustrous desire to be submerged in semen, it is a woman being told to literally shut up, take it and not make a face or she will not be paid. That is not the type of 'want' you want between two people. Two people in love and doing something in the regards of drinking semen is totally different, they want to do it because there is no forcing or pretending.