A day at the races

A bloke was having a few drinks by himself at a London casino when he met up with a striking but quite short and slim young woman. They got on famously and ended up in bed. 
  
The next morning she told him she was a jockey and that if he came to the races at Ascot that day, she'd tip him the winner of each race she was riding in by giving him a sign as she rode out of the saddling paddock. 
  
In Race 2, she rode out rubbing both her boobs. The bloke looked through the race book and found 'Two Abreast' on which he placed $100 at 5-1. It won by two lengths. 
  
In Race 4 she rode out rubbing her fingers round her eyes. He put the lot on 'Eyeliner' at 10-1 and was then $5000 in front 
  
. 
In the last race she came out standing up in the stirrups and rubbing her growler. He backed nothing. 
  

After the races, he met up with her and thanked her for the winners in races 2 and 4. 'What about 'Itchy Mickey' in the sixth?', she asked. 'It paid a fortune?' 

'Sh*t', he said, 'I thought you were telling me the favourite was scratched!'