I make big cakes for lots of people sometimes, and I'd find it a bit strange if the organisers/birthday boy/bride and groom chose their favourite flavour cake if it happened to be something that not everyone would like. They want their guests to enjoy the celebration - not have solely what they themselves would prefer. Then they can go and get their own key lime cake with ginger frosting at another time.
Is there a truly universally-liked flavor, though? Just about any kind of cake that I can think of, I know someone who wouldn't eat it. As a simple example, I've known a couple of people who don't like chocolate. I also know someone who won't eat any kind of cake unless there is chocolate involved. (She is watching her weight, so she has to really like the cake to make it worth the calories.)
When I make Halloween cakes for the office, I make both chocolate and non-chocolate cakes, one in the form of cupcakes.
No, of course not. But I'm talking about pleasing the majority, or at least, not displeasing the majority, for a large event. And in the OP's case, which is a small event, we know that one of the attendees doesn't like chocolate. So maybe there's a second choice that would make the everyone mostly happy, and the birthday boy can make himself deliriously happy at another time.
It seems to me, though, that birthday boy would
be really happy if a cake alternative was used, such as a pie. He seems to be just the type who is picky about his cake, "cake" being the operative word.
If he were insisting "You must
give me a cake and it must
be chocolate" that would be one thing, but I don't think he is. It seems more like he's saying that the only kind of cake he likes is chocolate but he also likes pies, etc, and one of those would be perfectly fine by him and would appeal to all the guests. And the one who wants to bring the cake is the one insisting it must
He's willing to compromise, but the one who wants to provide the cake is not, it seems. And she asked him specifically what kind he wants, so it seems to me that she really should bake that kind, if she insists on a cake. If she didn't want to make a chocolate cake, she should have offered specific alternatives, like some previous commenters have pointed out. To ask "what would you like?" and then say "no" really seems the height of rudeness to me.
As much as I don't understand it personally
birthday boy just doesn't seem to be a big fan of cake. At this point, I personally think that the best solution would be to have a cake in a flavor that the others like and also some kind of pie. That is, if there has to be an actual cake at all.