Pay me in nature
Exchanging services and favor for other physical activities, mainly sex. For example, a friends asks you to help her move her mattresses to her new place and says "How can I repay you?" and you say "You can pay me in nature." :)
A: "Hey man, can you give me a ride from the airport, I'll pay you back!"
B: "Sure, I'll be there. You can pay me in nature."
B: "Sure, I'll be there. You can pay me in nature."