My Girlfriend goes on my Facebook?

[john]

My girlfriend occasionally goes on my Facebook, fyi we have been together for 3 years. This started because one time i needed her to log into it to find something in my messages for me. Since then I know she occasionally logs into there to "check up" on me I suppose. I do not feel like changing my password because currently it is easy for me to remember and I trust her. I have nothing to hide but it bothers me that she does this. I have also noticed my friends list gets smaller from time to time since she found out my password. Most of the women I was friends with on there are now removed and I did not remove them and it is unlikely they removed me. I do not assoicate with those women anymore and would have likely removed them anyways but it bothers me that she would go ahead and do that. What so I do if anything?