Looking forward to 1.7 and pregnancy content, I love your character designs!
I have some suggestions for the future!
I agree with others' suggestions that there should be more at the start of the game to initiate Anna's interest in MC, especially if it's going to be revealed that getting closer to him was her real reason behind her making the Starmaker page. She could walk in on him in the shower, or he could comfort her after an argument with Josef, or he could overhear her and Josef discussing their poor sex life. These could all be pre-scripted as part of the story's progression so that players can't miss them.
In the slut route, with Josef staying, on Fridays there should be an alternate version of the master bedroom scene with Anna, where MC would impregnate her behind Josef's back, on Josef's side of the bed. She could really play it up in her dialogue about MC fully claiming and stealing her from Josef right under his nose.
If sharing Anna with Adrian but not Josef, and Josef stays, there should be random hallway encounters between Adrian and Josef where Adrian awkwardly has to make excuses for MC, Anna and Adrian spending so much time together. A similar encounter could occur between MC and Josef with Josef asking why Anna has been in Adrian's room so long with the door closed.
On Thursday movie nights, if you pick the Sci-Fi option, Josef should be so engrossed in the show that MC is able to grope and kiss Anna right next to him without being noticed. This would contribute to the slut route. For all TV choices, there should be an option for MC to innocently cuddle Anna and have that contribute to the romance route. If you choose "Watch the news" enough times, there should be a random chance that Anna will be the model the news reporter discusses, but Josef has conveniently fallen asleep just before that segment shows.
In the romance route, since MC cannot have sex with Anna in the kitchen, he should be able to ask her to join him in his bedroom for sex instead.
I think in scenes that are in both the romance and slut routes, there needs to be a bigger difference in both MC's and Anna's dialogue to differentiate the two routes more.
There should be a scene at the coffee shop with Anna and MC when Anna randomly visits. If in the romance route, they would sneak into the store room and make-out. If the non-sharing slut route, they sneak into the store room and she gives him a HJ and makes him ejaculate into her coffee like in the kitchen scene. If in the sharing with Adrian route and slut route, Adrian and Anna can visit at the same time and MC and Adrian can DP or spit-roast Anna in the coffee shop store room.
My craziest suggestion that would require a silly amount of work, is to have an "Adrian steals Anna from MC" route. The prerequisite for this would be Adrian staying, MC sharing Alice with Adrian rather than stealing her which gives Adrian confidence, and starting the Adrian / Anna sharing route. During the initial stages of Anna seducing Adrian there should be an interaction between Anna and MC where MC asks her if she is enjoying it, she says yes, and MC can follow up with "Good, I knew you would" to continue the sharing route, or ask "More than you enjoy it with me?" to be playful, but then Anna would become shy and say "D-don't ask me that!" and then run off. The next time MC speaks to Anna in the kitchen, she says she thinks she can handle her Starmaker page on her own from now on and all scenes between MC and Anna stop. If MC heads to the studio on a morning after this, Adrian will be taking pictures of Anna in one of the outfits, and Anna will ask MC if he needs anything then shoo him away before he can question why Adrian is there. From then on, all scenes that would normally be between MC and Anna would instead have MC catch Anna and Adrian in suspicious situations but not actually having sex. For example driving to the park on Wednesday will find Anna and Adrian walking and Adrian's arm would be around Anna's waist. Going to the beach on Tuesday will find Adrian applying sunscreen to Anna's naked body. Adrian will be helping Anna stretch during the living room yoga scene. Etc etc. Any interaction that would usually contribute to the slut or romance route, or are focused around MC helping Anna, instead become about whether Anna will come back to sharing with MC or continue to go to only Adrian. For example, refusing to drive her on Fridays will make Adrian drive her instead, MC could go to the flower shop to pick Anna up and find Adrian already there, random chance each day that Adrian will buy the groceries and flowers for Anna. Etc etc. If Anna continues to go to Adrian then the scenes should escalate, so that it's obvious that Anna and Adrian were having sex or doing something sexual just before MC arrived at the scene, but MC would not confront them about it due to insecurity, and on Tuesdays attempting to enter the shower or Adrian's bedroom for gaming would result in a locked door and moaning coming through the door. The next escalation would be MC unable to find Anna in the kitchen, and going to the studio and catching Anna and Adrian having sex for Starmaker pictures. After that, all scenes will now be MC catching Anna and Adrian having sex and watching without interrupting. There would be several hallway interactions with Josef where MC has to cover for Anna and Adrian, or awkward interactions between MC and Adrian. The final escalation would be MC finding his own bedroom door locked and spying through the keyhole as Anna and Adrian have sex on his bed and Adrian impregnates Anna. The upstairs hallway scene where MC spies through the keyhole on Anna and Josef having sex would change to be Anna and Adrian having sex in the master bedroom. On Thursdays Anna will drive Adrian to chess club but if you go to the parking lot in the badlands you can catch Anna and Adrian having sex in the car. If Anna returns to MC before the final escalation, she apologises to him and the game returns to the normal "Sharing Anna with Adrian" route. Obviously this whole idea is ridiculous because you'd pretty much need to redo all of Anna's artwork, but I think it's a cool idea.
Anyway, keep up the great work!