my boyfriends in Cuba with two of his close friends?

My boyfriend left for Cuba for a week with two of his close friends... Both of his friends are guys and they both really like me and approve, and I trust my boyfriend 100%... But all of my friends are saying that they'd never let their boyfriend do the same bc they're scared of cheating, and I don't want to say that cheating hasn't come to my mind, but I honestly trust him so much, I guess I just have my insecure moments here and there? But is it wrong that I think that way? I never brought this issue up Witt him but he knows I've been cheated on before so I feel like he knows how I feel about it. I know he wouldn't do anything but there's always that little thought