Is this unreasonable?

My roommates are having a birthday party tonight, the party isn’t the problem I’m in a sorority like I party too. And I don’t care about the noise, etc. The problem though is that someone has been hogging the bathrooms all night, the downstairs and upstairs ones. When I tried to ask to use the restroom, because I had been waiting for so long, they looked annoyed with me. The downstairs bathroom is fine, but is it unreasonable for me to ask them the next time they host a party to not let their guests upstairs unless for like an actual problem or something? Especially because this party has lasted like five hours atp… lmk