For increasing the all-around tension of at least two families, there's nothing as effective as a wedding. You're throwing strangers together in a situation that may be alien to all of them. You're encouraging a clash of styles and tastes, with you and the person you love most right in the middle of it.
It seems like a situation wrought with danger, disaster, and debt. But there are ways of defeating all the monsters between you and the wedding of your dreams.
How about