I get the going out and it's to be expected. Any of them being married or having partners means nothing in my book. In this situation it boils down to your trust in your partner and hopefully you know some of the friends and their history.

Having said that, he's apparently lying to you, and disrespecting you by not being an adult and having a real conversation about what's going on. He's going to come home and spew some BS about you ruining his vacation, but what really happened is you called him out on his behavior and he is throwing a tantrum.