She's just having her time, chill, relax, relationships often get broken up because of a misunderstanding, and right now, if she still truly "loves" you than the other boy she met during her vacation, then you got no reason to be pissed at her. At least she told you the truth? Won't it be worse if she kept all this away from you until later at a certain time? She told you the truth because she wants you to understand that she still loves you, she's still loyal to you, she's still yours.