Yes the humans have always distinguished themselves from the animals by changing quite a few biological features called as evolution. (Moving on two limbs
though built to move with four is just once such feature). So we do copulate face-to-face, looking into each other's eyes and all. Though some of the fairer sex prefer to keep their eyes closed for various reasons.
This brings us back to the discussion.
From a evolutionary outlook, the biological programming is definitely for the proliferation and sustanenance of the species. Consent is vital. Hence many people (supported by social customs) inculcate and follow the relationship before copulation format. Thus there is a good chance for passing of genes and their survival.
On the otherhand question of pleasure is a completely different orientation. Only when the above evolutionary trends are satisfied does the
sexual copulation for pure pleasure arise. Then f relationship before copulation (howsoever thin the relationship might be) does not remain a very strong point.
Security in the society of fairer sex, will bring changes to biological feelings and this again will be called evolution.
