Hay riding 

Being high or stoned due to smoking grass or eating marijuana infused food.

Dude what did you do yesterday?
I was hay riding in my girlfriend’s basement.

Hay riding by Dawaninon December 12, 2009

hay riding 

When one takes a bus into the ghetto for a cheap thrill.

(South side of Chicago at 1 am)
Bus driver: "Kid what are you doing way down here? Hay riding?"
Student: "No, I fell asleep and missed my stop and need to get back north. Thanks for stopping."

hay riding by UrbDickler October 28, 2010

hayriding

sitting in the back of a pickup truck with grass in the bed of the truck with that special someone

"Are you guys hayriding?"
"Yes, every Tuesday."

hayriding by g-blay October 4, 2011

Hagriding 

The act of having Hagrid-like hair whilst riding your bike around town with your arms perfectly flexed at a 90 degree angle while simultaneously swinging from one side to the other in order to maintain balance.

Oh WOW! Look at that girl hagriding down the road!

Hagriding by Mr. Potter Harry September 25, 2018