Sex as defined

Duty- if done with your  spouse

Art- if done with your lover..

Education- if done with a virgin..

Tuition- if done with your teacher..

Job- if done with your boss/secretary.

Science- if done with a fertile  person......

Business- if done with an escort.

Social work - if done with your neighbor

Charity- if done with a widow/widwer or somebody seeking it......

Sacrifice- if done with your own hand or as a self service ...