(In reply to a post stating that because we do not always have sex to procreate, talking about sex having the sole function as procreation would be incorrevt)

It is a means to and end...pregnancy.
In that it is the only natural way of procreating.
If you abstain you don't get pregnant.

The mouth is for speaking and it is the means for getting food to the stomach.
Because you use your mouth for other things does not mean it was designed for those things.
Somethings were created/designed to be used by the mouth.

However the natural functions are speech, eating and breathing.