I am a very outgoing and expressive person and by some standards, a flirt. In the past I have been a bit oblivious to other peoples reactions. As I have grown I am much more in tune with perceiving others reactions from what they say to body language etc. There have been some times in the past that I have gotten some awkward and uncomfortable responses and now I am much more careful but by no means less friendly or outgoing. I would not get along with someone that did not like that or wanted me to change it.
The only aside I will make is that if he is with you and completely disengages from you to talk with others I can see how that would be an issue. When I am with someone, wife, friend or associate, I am no less outgoing but I always introduce and include those that I am with. If the folks I am with wish to excuse themselves from a conversation they usually do. If you find he acts like you are wallpaper when he is making nice I would say something like "Hey honey, I have always loved your friendly and outgoing nature. I have noticed lately that when we are tog eather and you strike up a new conversation, you neither introduce me or include me in the discussion. That makes me feel isolated and unimportant. I don't want you to stop being friendly, I just want you to include me.
While I think we can gather his personality type or communication style, I wonder what yours is. If you are shy and reserved I can understand how you may be polar opposites. One thing that you keep saying really bothers me though. You keep mentioning that you know how women think or that some women may see it as opportunity. Neither you, nor he can controll how others react or what they get up to. Just by sheer probability we all will run across people that are attracted to us and some that do not share our convictions or moral code. What is important is how we respond.
If you love this man, or anyone for that matter, you love him. You must love others for the total package. You cannot love someone in spite of their faults or the things you think they need to change. You must love someone FOR their faults...and all the good stuff to.
If you trust him and believe that he honors you and would not be unfaithful then I suggest that you learn to love it. I would also suggest you take some time to be introspective and be honest with yourself about the insecurities you may have.
I am engaged to a very beautiful and very outgoing lady. She is the type of person that turns heads and lights up a room. She is never at a loss for attention and will engage nearly anyone. I know there are people that get the wrong ideas and there are people who's intentions are not as pure as I would like. I have seen and know of plenty of times she has to rebuff the advances of others and she always does so with kindness and grace. I know I have two choices. I can love her for who she is and trust her love for me to always do the right thing. On the other hand, I could try and change her. If she were less outgoing and friendly then it would reduce, but not eliminate those with other than honerable interest in her. I will always choose the first. I know that trying to get her to be something or someone she is not would only result in building frustration and resentment.
I cannot tell you if you are right for each other. I can say, based on what you have said, that if either of you requires a drastic change in personality to be a fit for each other than it is unlikely to work and you may not be the one to decide that first.