Love is a fine art.
If he goes far, let him go. Stop nagging and he will fall back. Boys are kiddish at times and they do enjoy company of other guys more than their girls due to ‘dirty talk’ factor.
What ever, just ignore him when you really feel hurt. Soon he will realize his mistake.
Nothing kills love more than neglect and nothing nourishes it more than neglect!
It all depends on perspective and timing.