Weddings are also a social commitment exercise to the couple. Imagine if you had break a promise you made in front of everyone both of you know, after spending a whole lot of money. It’s loss aversion and social shame that possibly made a lot of couples stick together. Even so, posing with your best clothes, food, locations, entertainment and donning all of your jewelry (all of your wealth in gold in some country) does likely play the Envy string too.