Don't know if I should break up with my boyfriend

Hi everyone, my bf and I have been together for almost 5 months now but we were seeing each/good friends with each other for about a year before that. During that time I knew he liked me but I'm also aware he liked another girl but "chose" me. Now I find myself getting attached. The thing is I have always viewed him as a bit of a player and what's happening now is I am continually feeling insecure about our relationship bc there is no trust. He believes it's okay to get to know another girl through lunch while we are dating and that isn't okay with me. The reason I'm feeling insecure about us is bc he went out with this one girl for lunch and didn't tell me, and althoigh I've stopped responding to snapchats and don't use it often, she is now his best friend and has been for weeks. They are also starting to like each others fb photos now. I know these are small things and he has only slightly changed attitude towards me or maybe I'm just paranoid... But I feel like he doesn't care as much if I don't respond to his texts. He still says he loves me and we still go out but am I over reacting? The reason I'm contemplating breaking up with him is bc he always mentions his going out habits leading to his previous breakups and how he wasn't willing to change for her He isn't going to change for me and I don't expect him to but I am not comfortable with the way things are going. Sorry this is so muddled and long I'm typing on my phone because I'm on holiday and thinking of breaking up with him. I feel so bad its ruining my holiday. Any insight or suggestions would help.

You are not over reaching. Going out to lunch dates with another girl would be a big no-no for my boyfriend. You need to have (and all relationships need to have) the sit down talk where you each tell each other what you are and are not "ok" with. You are not ok with this and he needs to know that. If he does not respect that then you should find some one who does respect how you feel. You should be your boyfriends best friend. Not some other woman. If he is ok with getting to know another girl over lunch and is ok with having a girl friend who is fine with getting to know a guy over lunch then that is who he should date. If you want a relationship that is different then you need to tell him that. Not every relation ship works and you have found one of the reasons. Your boyfriend and you need to sit down and find a middle ground (maybe you are ok with him hanging out with her in groups or with you) or maybe you two will find you are not compatible on this issue and need to separate. But remember when you wrote "He isn't going to change for me and I don't expect him to" that is wrong. People do change, they do it everyday. They stop being selfish, they realize what was really important, they come to understand that their behavior was hurting a person that they care about and they stop it. Expect to be treated well and do not accept less. If he feels like this new friend ship is more important then your relationship with him then all the more reason to get out of the relationship.