Sorry for asking again.
About the "Gave birth to a monster",when will you know you master the Voice? I tried several time at different moments in the game and allof them ended up Jessica gave in and let Paul had his way instead of denied him, so I am not sure about the timing
I didn't want to pick on you specifically, it's just that lately people have become lazier and lazier in asking things and it seems nobody cares to check first if there is already an answer. Sorry if I sounded too harsh.
When you ask Jessica to teach you more of the Voice and she says "not bad, try it discreetely on the Fremen", you have learned it. The condition that triggers this answer should be having reached the first spice harvest objective (time acceleration).
From then on it's a matter of trying and trying, after 4 or five times you she will submit to your voice and give you a blowjob.
Do it too many times (it doesn't matter if you ask for bj or sex) and you are in for a very nasty surprise.
By the way, if you are interesed in the marriage scene, when she says the phrase I wrote it's the moment you should completelly stop to try the Voice on her (use it even one time more and you will miss that scene).
So the two scenes are mutually exclusive.