Warning; advice given is NOT politically correct!
"Dear Winifred; I've got to get this off of my chest; I absolutely hate the lunches my wife packs for me. Is there any diplomatic way I can let her know without causing marital trouble? Signed Between a Rock and a Hard Place."
"Dear Between a Rock and a Hard Place, first of all, don't you mean Between a Rock and a Limp, Flaccid Place?, at least according to your wife? Now, in answer to your question; you could come home from work right after lunch and say you need to shower off the disgusting gut-juice you're now wearing after you got brave and attempted to swallow the absolute shit in a sandwich bag she made you for lunch; beyond that? You're shit out of luck there, skipper. Maybe divorce? Winifred."