That's why Fuckface snowflakes out about Josy and Maya no matter whether you were trying to fuck neither/either/both of them, because that was required for the main storyline. It's why Fuckface freaks out about Sage's parents no matter what you've done with Jade/Sage/Tybalt, it's required for the main storyline.
those are two moments you can't compare
it is the player who may or may not be interested in Maya and Josy, but MC is. he has had a crush on Josy since before the game started.
instead with the "fuck, fuck, fuck" there are several situations that are compeltely in the hands of the choices made by the player
the problem is not the shock, but that this is always the same (a situation that has somehow been corrected with the interlude) whether MC has just found out that he has had sex with his "mother-in-law" or whether he has "only" found out who her friend's adoptive parents are
in addition to this difference: that MC is taken with both girls serves the plot for at least the entirety of a chapter, that MC is upset with Sage's family served only to DPC to give a twist closure to the chapter, a twist that for a great many players will vanish completely at the beginning of the next chapter