The "Friend" Problem?

My boyfriend and I have a friend problem. His friends don't live in town and when they come to visit I feel very neglected. For the sake of trying to be fair, I do try to see where he's coming from. They are all around 25, and all beginning to start their own lives, and soon, the time that they do get to spend together will be even less, bc of families, and careers, and distance, etc. So, I can understand why when his friends come to town, he chooses them. However, is it wrong for me to want him to choose me just once? I feel like we have been dating long enough (1.5 yrs) that I should start becoming a higher priority to him than this. The major problem I have, is with them going out at night. They go out to the bars, get smashed, come home at 2:30, and stay up for another 3 hours. I DO get invited. I get invited to a lot of the things they do together, but a lot of the time, it's not much. Just sitting around nursing hangovers, or getting drunk, or eating fast food. I just wish, that like my friend's boyfriends, he would attempt to find things to do that everyone could enjoy (including me). This has caused major fights. In fact the majority of arguments that my boyfriend and I have hinges on this issue. Recently though we made a pact to each other. I know that neither of us are perfect and he is going to attempt and work on the friend issue, meanwhile, I am going to work at not getting overly upset at small issues (I will be the first to come out and say I have anger issues). I just don't feel like he is going to work on it, because he still will tell me, he doesn't find anything wrong with it. A couple days ago, his mom even brought it up while we were at dinner. She told him that he better not neglect me (his friend is coming to live with him for about a month). And she also told me that it will pan out. I said I wasn't going to let it bother me, because that's really what I'm striving for, but I'm not sure if i have made enough progress to do that. I feel like I need an alternate plan of action just in case. I need advice about how I can bring this topic up to him in a non-angry way, if, when his friend comes into town, I do get neglected.