Oh, you answered fast! I was either on hard or normal with the new sprites. I know that easy prevents stat bad ends. Thing is, I could get them before the update on normal/hard.
Just got flirty's bad end by slacking off until promiscuity and sexiness maxed simultaneously. When I max them manually and individually, nothing happens. Normal mode.
Unsure if a typo or meta humor: when you choose to not answer the door for the detached personality, MC says "I'm going to answer it. No one's going to tell me I can't" and then immediately answers.
Found another: 