Sharing Our Innermost Thoughts

i love my girlfriend but not when its like this. i feel like i tell her everything. like everything. she hears about ever little detail of my day. for example, someone told me yesterday not to tell my girlfriend about something…i did it anyways bc i want her to know everything. and today she tells me shes mad because something happened with that person but she wont tell me why?? she tells other people about this stuff but not me. why wont she tell me anything. does she not trust me enough??