Am I the asshole for refusing to share my college dorm bed after being asked to?

So in college, I'm a senior. I'm a guy who owns a California king sized bed (got it as a gift from my parents. It is huge). <br><br>This is the first year I'm living with a roommate. I came to find out he had girlfriend and he asked if she could also live with us, or at least have permission to be in our dorm during room hours. <br><br>I agreed, but asked that the bed be split. This is a couch/bed combo. The bed can be removed from the couch and just be a bed. <br><br>So, we divided it. We moved the bed to the far left side of the room, farthest away from the door. The couch, we placed in the middle, dividing the room. <br><br>To the right side of the room, we hung up a room divider. On that side we put my roommate's desk, bed and all his personal items. <br><br>So bascially, the room looks like this<br>Room divider<br>Roommate's bed/furniture<br>Room divider<br>Couch<br>Bed<br>Desk<br>Desk<br><br>Now, I'm not complaining, because I could just continue to use my bed. But I'm slightly annoyed. <br><br>His girlfriend (let's just call her Megan), she sleeps in the room 4-5 nights per week. And always on my bed. She'll sleep in my bed with my roommate, and I have to sleep on the couch. <br><br>Okay, cool, no problem. Except, when they leave for the weekend. That is, they both go away, to their hometowns, and no one is there on the weekends, I have to sleep on the couch? <br><br>Last night I decided to sleep in my bed, because 1, I payed for it. 2, I was tired and wanted to sleep where I was most comfortable. 3, no one was there. <br><br>So I sleep in my bed. Wake up this morning to a very angry roommate and Megan, who just arrived. <br><br>To sum it up, they went off on me, saying I crossed a line, invaded their space, and I was being inconsiderate. <br><br>I have to admit, I was a little drunk, but I don't think I was in the wrong here. <br><br>Am I?