am i being selfish? Please be honest.?

So my twin cousins family is coming to visit this weekend and my mom thinks that i should give up my room to my younger sister and the two twin cousins. I asked why couldnt they use my older sisters room and she said because my older sister always has to give it up. But i think my argument is valid because my older sister (who is a year older than me) goes off to college and half of her belongings are in her apartment and she is only back for winter break. i go to a community college very close to my house and i argued that this is where i come home to every night where i have pretty much all my personal belongings such as my games my laptop which is hooked up to a external monitor and such. I also have all my clothes and books and hats. Not to mention my airsoft pistols. I find it unfair that i have to give up my room because all my silbings and cousins are females and the fact that I (the only male sibling/cousin) has to give up my room. Usually in all the activities we do when they visit, im always the one that is left out anyway being the only one who doesnt have any common interest being a guy. I find it unfair i have to give up my "man cave". Not to mention i have to give up my room to 3 girls. Does anyone else find that weird? I mean im 18 and they are 15/16 highschool girls. Im already in my first year of college. What do you guys think? am i being selfish? please be honest. Thank you