When your having anal sex and someone pees in your asshole.
Girl: I was having a great time in bed until my boyfriend gave me a yellowtail.
(v.)
To urinate into someone's ass while performing active anal sex.
"Oh baby, it felt so good when you yellowtailed me last night!"
When a man accidentally pisses on the back of his underwear while sitting down to shit.
Sam:"why are you holding your boxers out under the hand dryer? "
James:"I totally was yellowtailing it while I was taking a deuce"
Smacking a bitches ass Profusely
Let’s go give a nigga yellowtail in the club tonight.