If you have no intentions of breaking up with your boyfriend and you will NEVER put yourself in the position you put yourself in this time, then why tell him? If you are going to break up with him then I wonder again, why tell him? Contrary to some peoples insertion that you should tell him, I'm thinking that there are times when confession is a selfish thing that only is done to alleviate one's own own guilt. This would be one of those times. Whether you stay with him or you go, telling him will serve no purpose.
Learn from this mistake so you don't repeat it.
I do hope you get over your personal insecurities so that you no longer feel that you need to hang onto one while you "cave" to the attentions of another. That's just unfair and selfish on so many levels. Surely you see that? Due to your wonderlust, you'd start on your journey to more self-respect and getting over your pseronal insecurities if you broke up with the LD boyfriend so you'll be free to pursue others without guilt and codependency.
That would be him respecting himself, CG.in fact, i found that he respected me,