Sam Sylk Show

Dear Sam, I had been dating this guy for 3 months. He planned a little romantic trip for us to go on. A week before the trip, I had to cancel because of a family emergency. He told me "no worries" but since he had already paid for it, that he was still going and I was like cool, I get it. The problem is he took another woman and was posting the pics all over IG. He claims that she was just a friend and nothing happened and also claims some of his other friends went too. But he was also quick to remind me that we only been going out for 3 months, and that I was being a little insecure acting. Am I tripping? Is it that we haven't been dating long enough for exclusivity? Help me out. Should I just leave him alone?