A = Vaginal
S = Anal
D = Blowjob
F = Handjob
in prostitution, the guy usually suggests what position/service he wants, if he asked for BlowJob, then you should mash spam D, it all depends on his request, but don't spam it too much, there will be moments where you have to stop for a short second, or else you will lose some credit.
If the guy asked for "Full Service" then you will have to figure out what is the current position Visually, he will be swiping at random from A to S to D to F.
if you have enough WIS then a new option will unlock, its "Ask for more", this will unlock a higher level for prostitution from Handjob -> Blowjob -> Anal -> Vaginal -> Full Service, you will still be able to use the previous service too, but Be careful because if you don't have enough WIS then the customer will have a chance to get angry and attack you instead.
Hopefully this is understandable ,:D
Viewing post in I want to learn more about prostitution
its not a whole lot more but it appears at 10 wis its servicable at 20 wis becomes risky at high wis due to you pushing the upper limits of what customer finds acceptable after the first ask for more so more just means less total asks and asking for more and failing causes you to get beaten and lose some morality