I can't believe you accuse me of trolling you.
I mean, really. As ridiculous as the notion is that someone would ACTUALLY fire someone for not eating a hot dog (it was a joke), your overreaction is equally ridiculous. Hot dog haters aren't a protected class and I suspect most non-government, non-union workers are employed at will.
If your employer asks you to attend a ball game, go. (This goes to JL too if invited to a communist rally / soccer game.) Show up late, thank the host for thinking of you, eat some food, nurse a glass of wine, mingle a little, leave early, go back to work.
I attended a SF Giants game once where I never found out who they were playing. It's a goddamn social event.