Cutting someones grass 

Getting/flirting with someone who your friend has already gotten with or 'shotgunned'.

Girl 1 admires boy 1
Girl 2 gets with boy 1 (cutting someones grass)

Girl 1 to girl 2: How dare you cut my grass!

Cutting someones grass by whatababeiam August 15, 2010

cutting someone's grass 

When someone attempts to pick up your woman.

"Am I cutting your grass here mate?
"Nah, all's good, we jus' friends."

cutting someone's grass by Diego September 16, 2003

Cutting Someone's Grass 

When someone comes to a group of people and asks to buy drugs and someone says they have that drug before you and you sell your drugs before they do.

- Does anyone have any pot?
- I do, I'll be right back I have to go get it. (leaves)
- Yo i got some pot buy it off me.
- OK
- Man, you're cutting someone's grass.

Cutting Someone's Grass by Shawn Maglicic December 28, 2005