A Bit of Slap and Tickle

 is an unmarked quest in Fallout: New Vegas.

Quick walkthrough
Visit the Casa Madrid in Westside and see how fast you can spend your caps! There is a choice for everyone, male, female or elderly female.

Talk to proprietor Pretty Sarah and have a good time!

Detailed walkthrough
In the Casa Madrid, you have three prostitutes to choose from: Sweetie, Maude and Jimmy. Sweetie is the house favorite, but also the most expensive. Having relations with her will cost 300 caps. Maude is the prostitute for those who "like their cheese well-aged". If your character is male, she can be hired for 75 caps. Jimmy is what Pretty Sarah calls "a specialty item". If your player is male, he will service you for 200 caps. So take your pick and have some fun!