These are general guidelines, research still advisable regarding sensitive themes.
To me they are all green flags as couples. It's organized from lighter to heavier narrative/the way they interact. Some at the middle are debatable when it comes to manipulation, jealousy, possessive, dub con, etc. The ones at the bottom -42 and below- cointain ( outside the couple ) 🍇, a***e, gore, violence, homophobia, mental illness, etc.