When a ML (maybe even WL and SBs) offers you extras at the beginning, during or towards the end of the session (regardless) and you reject/decline them because the price was too much or the girl is not your type or both parties couldn't negotiate/agree on certain things... Whatever the reasons for turning it down.
I feel a sense of awkwardness at that point and can't help to think that this will impact on the services for the remaining time.
I know it's hard to prove but does anyone else feel that way or is able to validate this from your experiences?