[taylalatbh.]

I think you should try and persuade, (nicely) that your boyfriend does come with you on this day trip. An hour and a half isn't too long away, and it does seem like he needs to get in their good books. Whether he's done anything wrong or not. He doesn't appear to have a valid excuse not to go on the day trip, so really try to get through to him that it would be a good day, and would make your relationship a lot better.