can't stand my bf

Don't get me wrong I love his family but they are honestly so bossy and nagging. Next week my bf is visiting me (long distance issues) and his parents just mentioned how he has to come back early now (he can only stay 5 days not 14). Because they are going on vacation that was last minute! It just drives me crazy that I can never ever just be with him without them interfering. He never says no to them and it just makes him upset and me. This was our only time together for the entire summer! His parents just planned the trip after me and him picked dates so I could take off of work. I just find it so rude. I would never make him leave his family for me, shouldn't they do the same? How do I get him to stand up for himself?