If they are always busy & don't give you enough time, it means they don't value you and are not worth your time.
Whenever you make plans, and they cancel, this is a big red flag. It definitely shows they don't care about you or your time & efforts.
In a relationship, it's about the US and not ME. So if they are always talking about themselves, that means something is wrong there.
If your lover doesn't listen to you and always talks about themselves, it is a red flag. In a relationship, the persons need to listen to each other.
If your partner is always criticizing others and complaining about things, that means they are not happy with their life ad not happy with you either.
If your partner has no interest in your dreams and ambitions, it surely means they dont care about you and are not worth your time.
If you and your partner have no clear boundaries and they always are controlling & insecure, then it is a big no-no.