A man, or sometimes a woman, who often doesn't engage, or never has, engaged in sexual intercourse and is in position only to masturbate, therefore only able wrangles their wrist.
A test where in you have a woman place her breasts on your forearm. If the breasts extend/fold over your forearm, she is said to "pass". A gauge for the breast lover.
My ex-girlfriend got way too big, but the sex was good and she had no problem passing the Wrist Test!