My heart is pounding

My so and I had an argument last night and it was really bad. We made up but he hasn’t really been replying to me all day.

He has been surfing at the coast with his male friend since yesterday and is today too.

We talked on the phone earlier and said we were still together, etc

I just saw on his friends Instagram story that they’re at the beach with 3 women

None of them look like girls he would “go for” but it just made my heart sank. They had a case of beer and he doesn’t even drink so idk if he is drinking. I called him ONCE with no answer. Idk what to think. What should I do? Before the fight he was actually showing interest and now he’s kind of just been blowing me off. Idk if he’s just fucking around with one of the women or what