to get it- refers to have sex.
and on the green- on the area of campus in which there is a large grassy area, the "green"
Example A: Get it on the green, get get it on the green
Example B: Would you like to get it on the green?
Only if we use prophylactics.
Is that consent?
Example C: Danielle, Would you like to get it with me? On the green?
Only if Patrick joins.