Honestly, sometimes I really don't get Japanese people haha. All of this could have been avoided if they were just direct about what they think and say, like, 'Hey! It's my birthday! :D' But nooo, of course not, because if things were that simple, I guess it wouldn't be an anime. I think they took this whole thing to an extreme, finding the most convoluted ways to say something without actually saying it directly. The level of imagination in this episode is crazy.