Advice please!

Ive been with my boyfriend 1.5 years- we are in committed a relationship full of love and happiness so far. Last week I flew to his home country to take a vacation with him and his family. The second night there I was super jet lagged and couldn’t sleep, so I was playing on his phone while he slept (I don’t have international data and WiFi is really spotty). We frequently use each other’s phones and I know he’s ok with me scrolling through his social media, etc.

Well, I’m on his insta which is mostly travel/hobby related and I see a couple provocative posts from a girl I don’t know, and she looks young (like teens) so I’m like who dis? My instincts told me to check his DMs and low and behold- he had messaged her “You’re gorgeous.” She only replied thank you and then there were no more messages. He had sent the message a few days prior, when I was halfway around the world.

I know snooping is seriously not ok. I felt instantly guilty for crossing a major privacy boundary but also incredibly hurt that he had messaged this girl while we were apart. I was so shocked to see this. Even though its was a tame message that didn’t lead to anything, I can’t help but feel so disrespected and wondering what else he does when we are apart.

The next day he knew something was up with me, and asked me what was wrong, but I didn’t want to confront him during the trip with his family. Now I’m back home in the states and he’s still abroad.

I can’t stop thinking about it and I don’t know if I can trust him. Am I overreacting? or should I confront him when he comes back?

Help!