Gambler Groupies

Whenever a guy is gambling, you can tell he's winning because there are sexy ladies on either side of him.

And the turning of his luck is easily conveyed via a few disapproving glances from the ladies. When they leave, you know what's happened.

These girls may be dressed like tramps, showgirls, or even classy ladies, but they are always good looking and seem to materialize out of nowhere.

Compare with the Paid Harem, who drape themselves on a guy because he hired them to do so.

Examples of Gambler Groupies include:

Anime and Manga

Elvis from Rio -Rainbow Gate!- has a group of girls impressed by his Awesomeness By Analysis skills. When he loses to Rio at the end of the episode, the girls leave him behind.

Reid picks up one of these in Criminal Minds as he plays video poker in a casino. He shocks her by walking away from his machine and giving her his two thousand dollar winnings when she says something that causes him to realize how to solve the case.
In CSI, two bodies of the week were women of this kind. They were running a con to steal the bankcards and PIN of winning gamblers by hanging all over them at appropriate moments.

Diamonds Are Forever. A man is gambling at a Las Vegas casino with a beautiful woman named Plenty O'Toole at his side. Unfortunately he loses all his money, so she dumps him and latches on to James Bond.
Seen in the first Iron Man movie, when Tony is playing craps (instead of accepting an award, like he was supposed to be)
Happens in Rush Hour when Chris Tuckers character is gambling.
In Get Shorty, the character Leo is a schlub who faked his death and fled to Vegas with insurance money. While there, he becomes an extraordinarily lucky gambler and is surrounded by these.