I think what you say makes sense, except some girls offer bbfs even though I did not ask for it, and Ive been a regular client for a long time So its not to turn me into a regular.
I guess it may well be a “client loyalty” perk to assure my return, but its such a slight incentive, it seems likely they are in no way repelled by raw sex, and may well gain some satisfaction, either in the act itself or in pleasing at least certain men and the sense of power that brings.