HiCustomer Thank you for asking your question on JustAnswer. By the way, it would help us to know:
-How long have they been divorced?
-Why do they have to stay in the same room?
-Why can't you go along?
-Could you explain your situation a little more?Thank you again for trusting us with your problem. Please reply as soon as possible so that we can finish answering your question.
All you can do is trust him that he doesn't want the ex in a romantic way but be there for his son, this could give the sons a false sense of them being together again so this is risky all the way around but it can be feasible your boyfriend can sleep with one of the boys and the ex can sleep with the other I very much doubt they would do anything with both of the boys in the room if that is what you are worried about but if you keep him from helping his son the ex could make you look like the bad guy because you didn't want his father to come help him with school. Tell him when he come back things are going to have to change and that he is going to have to make the ex be more independent and take care of herself that you are tired of her depending on him when she is alone it seems as though she does it because your boyfriend allows her to do so, he needs to put his foot down and make her have to find her own way.
They are doing this for their sons education and not as a family getaway think of it that way I can understand you being a little upset about this and even more upset about the rooming situation maybe if he can afford it he can pay to stay some where else and put them up in that hotel, just because the festivities are at that hotel doesn't make him obligated to stay there he can meet them there at the time it is suppose to start. Tell him you would feel more comfortable if he were staying some where else but I really don't think you have anything to worry about even if he decides to just stay there with his boys.