When a man asks "what to do if my girlfriend wants things her way," it's pretty obvious there's a power struggle on the horizon. If you don't stand up to her, you are setting the standard for the relationship ("This is how it's okay to treat me"). But if you do take a stand, the relationship may become contentious. Therefore, it's quite important that you proceed with caution.
- Check yourself. Is this situation new to you, or is this something that crops up frequently in your life? The answer will determine which one of you is actually the problem. If you're not used to people standing up to you, then you need to do some work on your interpersonal skills.
- Weigh the relationship. Is her need to have things her way outweighing all the good things about you two as a couple? Consider how long you've been together, how well you know each other, how she gets along with your friends and family and vice-versa. In essence, what you are trying to find out is if the fact that your girlfriend wants things her way is doing so much damage that you can't get past it.
Discuss the issue with her. Do not do so if you are in the middle of an argument. Bring it up when everything is good, and you are both calm and levelheaded. Once you have presented the issue, hear her out. Listen to hear, not to form a rebuttal. Be ready with solutions, so the conversation has a resolution, not just a problem.
- Come up with a code word or phrase. Either one of you can use it to stop a situation from deteriorating. Agree on a phrase, and discuss when and why it should be used. If she doesn't like your solution, then hear her out, but be aware that her refusal is likely a red flag that she is very controlling, and you should probably start seriously considering ending the relationship.
- Give things a chance. Once you've taken all the above steps, be prepared to give her a chance to become aware of what she's been doing, and stop it. If this is a lifelong habit, it could take some time to break.
It's possible that she likes her life exactly as it is, and there will be no changes forthcoming. That's not necessarily a bad thing. Couples aren't always a good match. At least now you know that if your girlfriend continues to want things her way regardless of your feelings, then she's not mature enough to handle an adult relationship.