She's Against the Bachelor Party
Flowers? Seating arrangements? Color schemes? These “vital elements” of the wedding probably aren't the things you're looking forward to the most. The bachelor party? Now we're talking. The stag night is every man's right. This last hoorah is your farewell to the single life in the company of your finest friends. It doesn't matter if it's a relaxing camping trip or a weekend of debauchery in Amsterdam, the bachelor party marks your passage into the married world.
So an attempt by your fiancée to veto this is very worrying. “If you love me, you won't want to spend a night in a strip club” or “I don't trust what your friends will do to you” may sound sensible, but should be resisted. She has spent years dreaming about the wedding and you have spent years dreaming about your bachelor party.
This may be a glimpse into your future; you won't be going on that bar crawl for Johnny's birthday, there will be no Saturday night poker or football game, and Frank's bachelor party? Forget it.
No bachelor party means no marriage.