Rimming is when the anus (bum hole) is pleasured by your partner's tongue, they can lick and spit on the hole to stimulate the thousands of nerve endings that are located there. The act of licking someone’s bum hole is very erotic and very pleasurable, however, it isn't always everyone's cup of tea. You must make sure the area is clean and shaven so that the hole looks desirable. It is important that the area is as clean and hygienic as possible.
Escorts might offer rimming (giving) or rimming (receiving) if you want to be licked make sure the escort is comfortable with this before the booking, you don't want any confusion in the bedroom.
Rimming receiving is when your partner is happy to get licked but might not wish to lick yours in return.