单身就是烦的英文表达是"being single is a pain/annoyance".
这个表达的来源可能是因为单身会让人感到孤单和无聊，而这些感觉可能会让人感到烦恼。
例句：
Being single is a pain. 我单身就是烦。
I'm so tired of being single. It's such a pain. 我太厌倦单身了。真烦。
Sometimes I feel pke being single is a huge annoyance. 有时候我感觉单身是一个巨大的烦恼。