Haven't played the update yet, but I supposed it is because Void wants his game Star Periphery to have some verisimilitude. Markala is simply way too big for Spacer to give her a blowjob.
& Tessa's wasn't!?
As i said, verisimilitude. Unless Spacer had a distensible jaw or Markala broke it (which would be rape - something Void already told countless times it won't happen) there is no way for that to happen.
Something similar already happened during Eleanor game over scene.
& similar statements (no offenses, just my PO) like this are starting to seem to be indicating that there just might be a fair sum of most people here who are beginning to forget the fact that this a "SCI-FI/FICTIONAL/FANTACY" game. Which means that this is a "make-believe" type of game, not a "make-believable" one..!
So, having & seeing the Mc's jaw expand down & out to some shocking obscene proportion, obviously shouldn't shockingly be out of pocket here..
But if there just absolutely must be a some believable/realistic/stereotypical (or wtf), reasonable understanding that fits the sum of your realistic imaginations outlook in all of this, then VP could decide (if he wants) to add in some kind of a new fetish/stat/ability, of a "double-jointed jaw" that mc doesn't just only end up discovering he somehow has from however, whatever forced or unforced way (which VP would obviously also be responsible for deciding on how something like this would fit it in with his list of accepted tags), but that he also comes to find out he likes this lewd BDSM type of painful feel of pleasure that it gives him & that he's quickly able to gain easy control over him having (realistically), but only to the point of where he doesn't just end up having be a double-jointed jaw that's easily capable of unwillingly dislodging out of place randomly while he's walking, or talking, or suckered punched from out of nowhere (or all three). But with all the while, it still not being something he just has full absolute control to dislodge or even fully prevent from dislodging at will while outside of the everyday "jaw normal situations," because of its made key main fact of it being a specific sexual obscene ability that only someone who's just like Iris (a BDSM-Mistress) are capable trigging its ability at will whenever they want to it..!!?? (With a stat check that makes either easily, or uneasily for the BDSM Mistresses to also do so!!)
& then so that way with all that being possibly considered, we can obviously all (obviously not all) be sort of happy with this kind actual real, but somewhat unrealistic fetish being (enough for most standers) realistically fitted into this already great, (but still, remember) unreal, story!!