Early and long relationships- the girl is usually unsure of what is going on early on in the relationship. She’s not sure what to expect out of the relationship. In my experience, most girls are not fully focused on the relationship until a month or two into it, once they know it wont be an early flake. Longer relationships can be broken because usually the people will have been together so long, the girl will feel the need to experiment and try new things. 

So how do you act around her to keep her interested in you and break the interest in her boyfriend? It’s quite simple. First off, you’ll want to hang out with her a couple times a week. Nothing too extreme. Time spent together is all about quality, not quantity. Quantity may be important to a certain point, but quality is much more important. Now because she is in a relationship, she will most likely bring him up in conversation. Most guys would view this as a bad thing, but you are different. You know how to use this for your advantage. You want to get inside her head and change her mind about her boyfriend. So, when she says things that her boyfriend does, you simply compare yourself to what he does. For instance:

Her: my bf bought me flowers for my birthday

You: that’s all? Pretty weak on his part.

You want to instill doubt into her mind. Pound it in. Every chance you get, do it. This does not mean you go around saying, “Your boyfriend is dumb” or “Your boyfriend is an idiot.” Make the situation relevant. You want to make her think that you are a better catch than her current boyfriend. Think about it: if she can have something that is the same of what she has now, why would she change? But, if she thinks that you are better than her boyfriend, she just might be willing to oust him for you. If you are doing your part of instilling doubt and making you seem better than him, it will be very easy task of getting her.