True friend or just having fun?

I been treated badly this few days, seem I know something that she hide behind me. And I don't know what's the big deal that she not telling me all the truth? Is not the first time I know that by myself or from the other people. And I know that I treat her as a Friend that can talk and tell her all about my life, even that I brought her to my night life and intro all my friends to her. Is really enjoyed and have fun thought those entertainments. I know that she may not have the same thinking with me. I know I can't blame on her, it's because everyone have their own choices. It's between I may be her true friend or just having fun. She is one of my close friend. A friend that quite often went out with me to almost every clubs. I treat her not bad, but i don't know why, she like keeping everything, keep secret behind me, and just like i will blame her or jealous with her. I'm not, i just feel sad and mad, why she have to keep secret behind me?

Is that shame of clubs?
Is that shame to let me know?
Is that scare of my jealousy?

I may too straight for everything, I talk straight, I show my anger once I mad. But I m not jealousy, her everything making me feel like I had been used by my friend. The feel is difficult and different. When we went for clubs, we together, but once i been grounded, she totally the different went to club. Maybe we dint together went to club for a period, she will never know that what's wrong with us. I'm super surprise when I saw her on Friday night, and know quite more about her things. She's not letting one of our friend to tell me that she is with them when they are going to club. Once I know it, I'm totally feeling down, what should i do? Am I think too much? As I know this is not the first time I have this feel......

Speechless~ Thanks for those who consult me.

True friend? or just entertaining?

Goodnight, Miss Kelly