Make sure to keep visiting Laura in the mornings for breakfast by herself until she makes you a sandwich/you contaminate the sports drink for Jessica.
Then in the evenings check the location tracker to see when she's in Grace's apartment. Repeat those Grace events until they ask you to make them tea. That's when you contaminate the drinks and corrupt them both, unlocking the massage scene progression plus other stuff with her such as this:
(Make sure you did the lobby event with Laura 3 times before doing all written above)
Btw Dev if you're reading this ignore the hate, you've taken the criticism well and I look forward to you improving the game.
You're cooking with gas man, just please make this game less grindy its highkey ridiculous lol.
Maybe make daily interactions with the girls give you relationship points rather than ultra specific ones.
Also put a point system with a numerical value rather than showing hearts. You say an event may need 15 or 20 relationship point but we know fuck all how much points a character has. Faster text speed, autoskip for repeatable events, streamlined event progression plus some other tweaks and I firmly believe this will be one of the greats!