Riverton Wristwatch
When receiving a hand job, the man's ejaculate lands on the female's wrist and, by gravity, runs around her wrist. This creates the look of a white band on the woman's wrist. Popular because it normally requires just 2 to 4 ropes.

I remember in seventh grade at the movies Courtney gave me a handjob. I came so quickly, she got a Riverton Wristwatch.
I'll never forget the Riverton Wristwatch I gave her after a nice HJ.