The girlfriend should not speak with the main character about her issues. You can't steal someone's partner, that person made themselves available to be taken. She is feeling insecure but it is for him to set boundaries on his friendship for his love life to blossom. If he is not willing to do that, his affection for his girlfriend is not strong enough. If you have to do all of this complaining and making others see you in such a negative light; leave. It isn't worth it for your sanity. I only read the first chapter so I will not cast the girlfriend as the 'villain.' Though I am sure that is the path this plot will take. The man she is dating may have several pros to his personality, but there are bound to be cons. One of his pros may be nurturing those around him, but it becomes a con when you are below others in regards to his time and affection, or on the same wave length as everyone else instead of being seen as special. She was being petty to chose the day the two friends celebrate together. Especially as she did not ask for the birthday, seemingly on purpose; which would be more understandable.; but the day when the friends and their families come together to celebrate the pair. She may be testing the main character's reaction, trying to guilt her, or just plain bullying her into submission. However, in real life, if she pushed the friend like this, especially in a way that could be considered mean spirited, the partner may leave. Communication with the boyfriend seemingly does not work. At this point she should count this relationship as a loss. He may seem great, but the mental stress something like this may place on her is not worth it.