Article: If she frequently sulks when you disagree with her or when you tell her you're unavailable to do something with her, it might be time to get suspicious. If she seems upset when you don't do her favors that's a very bad sign. People are allowed to be upset, but they shouldn't use their emotions to manipulate you. For example, if she gets upset when you don't buy her meals or presents constantly, you should consider what her motivations are. Consider whether she is willing to return favors. People in a healthy relationship should be willing to make small sacrifices to support the other person. This doesn't necessarily mean spending money; it's an even better sign if she is willing to change her plans (within reason) to support you at important times. If she tells you that you can't hang out with other girls because it makes her worried, you should take a step back and assess the situation. It's one thing for her to express that sometimes she worries about other girls, but it is entirely different to forbid you from hanging out with your female friends. That is considered manipulative and controlling. Hearing her say that she couldn't take it if you left her may seem flattering, but this is still blackmail manipulating you into staying. If she threatens to tell your family or friends about something you did unless you do what she wants, that's the sign of an unhealthy relationship. If she tells you she is going to go out with their friends every night this week until you clean up the whole house, that is also blackmail. It may be more subtle than those examples, so take an honest look at her behavior. It's not healthy to constantly feel guilty in a relationship. If she often says things like, "I would never expect you to do something like that" or makes you feel guilty for hanging out with your friends because it makes her too lonely, you should take notice. Your partner should be supportive; she shouldn't try to make you feel guilty. If you wanted to go to watch a movie one night but she demands you throw a party at your house, or if she wants you to quit your job so that you can spend more time with her, she may be trying to manipulate you. Both of you are allowed to make reasonable requests to the other. The alarm bells should ring when she demands you change plans for a trivial reason, or gets upset when you decline.

What is a summary?
Watch out for angry outbursts. Be wary of jealousy. Beware of blackmail. Don't fall prey to guilt trips. Pay attention if she demands that you give up your plans for her plans.