Gravel rash is a term used in the gay community, to describe their first anal sex experience, as often the sphincter is very tight, and may produce a rash on the tip and shaft of the erect penis.
Trent: "Man, my first anal sex with a guy gave me the biggest gravel rash on my fucken knob aye! Luckily with time, the wounds have healed and so has my gay sex life!"
Medium to large piece(s) of sharp rock protruding through the surface of a gravel road. When viewed, look somewhat similar to seeing a shark's fin moving through the surface of water.
I hit a Gravel shark while driving and had to go and get my flat tire fixed at the tire shop.
the art of sodomizing a young chapette or chap with the shits whilst doing reverse cowgirl before pulling out so they can proceed to pebble dash your upper body
"dude she was such a kinky bitch she gave me a graveljacket, on curried sprouts night!!!"