Let's develop this a bit. If we compare all the characters in SOTS, they live in a city with a virus that makes them have greater sexual desires, so it's normal that in this case you don't need a position that allows you to progressively bring them to that desire; they have normal everyday lives. In the case of Grace and Julia, they live in a place totally isolated from the rest. Grace does make progress because she has never experienced anything sexual, not even a conversation with her parents, nothing that leads her to that desire. That's why we went from having the first encounter in the apartment to being the first to have DP with a dildo, so her progress makes more sense. Julia, on the other hand, is a Housewife who has been locked away for a long time, whose only activities are her family and going to church, nothing else. Her life has been like this for a long time. She is a frustrated Housewife with desires that she discovers a little at first, but after seeing Grace with Ethan, that desire changes. On the other hand, unlike other main MILFs in other NLT games, Julia doesn't have a female character that drives her to that progressive desire, in Lust Epidemic we had Amanda Bancroft and Amber (and with the help of the serum as the main trigger), which drives her to have a progress with the typical, Handjob, Blowjob and so on. IN TON, Janet is driven by Naomi, who makes her have that progressive desire and in Genesis Order, Carol is driven by her sister, Heather. But Julia, doesn't have anyone to drive her to that progress, she doesn't have female friends, her husband hasn't satisfied her for a long time, so her repressed desire grows very quickly, and makes her have that desire after seeing her daughter with Ethan, seeing that her husband is stupid and has a person who really understands her, that's why she lets herself be fucked so quickly. It makes completely sense as character development