A salty solution left on a man's penis that may be invisible to the naked eye from events such as 1) a long, hot training session 2. Reminisce of sperm after masturbating, or 3) an unannounced premature ejaculation upon oral sex.
After a long training session John went home and gave his wife a salty churro.
Or
Betty was talking to her friend Marie and said, "last night Dan gave me a salty churro".
Or
After a long ride, Andrew arrived to a dinner party and thought he'd be generous by offering the guests a salty churro.