A few weeks ago my group of friends rented a cabin for a vacation trip during winter break. 4 different couples were going plus a few single people. Most of us were coming from different cities as we were all home for break, so like 4 different cars all met there at different times. 

My girlfriend and I drove by ourselves, plan was to all get there at 1 then go grocery shopping. Pretty much everyone else is running late and we're stuck locked outside with one other couple for maybe an hour and a half. No big deal, we drive into town and get some food. While we're eating our friends start talking in the trip group chat we made, one of the girls (coming with her bf) had been sleeping on a couch the last week and asks if itd be ok if she can have one of the beds. Totally reasonable, no issues. Then another girl (also coming with her bf) sends a screenshot of one of the beds from the airbnb saying "(bf) and I call this one" followed by another screenshot of another bed saying "(first girl) told me she wants this one". My girlfriend and I are reading it laughing like, seriously? We're calling beds? Someone in the chat says something along the lines of can we just figure it out when we get there but conversation shifts to getting groceries and things and it gets dropped from there. 

So my gf and I are slightly annoyed. We had already talked about being fine sleeping on couches if we had to, that where we slept was not a big deal, but calling dibs 2 hours ahead of time just seems childish. We go back to the cabin and are able to go inside this time since its past our check in time and check out the place. Of course the 2 beds our friends have called are the only 2 private rooms, the rest of the beds and couches are in open living rooms so you'll be "sharing" the room. 

So one couple who called a room shows up next and is unloading. After a couple minutes I make a comment about them knowing the layout of the place and calling the private room when no one else even knew what it looked like (they had booked it on airbnb). Admittedly saying anything here made me an asshole, and I should have just let it all slide rather than make it into a big deal. Slightly blows up with them saying that they did the work renting it and so shouldn't they get to choose the room? Thats fair and I'm fine with them having it I'm just annoyed we had to play the dibs game with it instead of just figuring it out when we got there. 

After talking I totally made it sound like I thought my gf and i deserved the room cause we were there first, which is not at all what I actually felt but I let it die to avoid starting it again. So I understand that I came off as an asshole, but am I the asshole for being annoyed at them calling rooms? 

TLDR: group trip to a cabin and 2 hours before people arrive couple friends send screenshots of the specific bed in the cabin they "call". The 2 that are called are the private bedrooms and the rest are in shared rooms. 