Continuity mistake: When Lance arrives at the church to call off the wedding, he exits an old model cab with a square body. As he's walking up the church stairs the cab pulls off and is a newer model.
Continuity mistake: When all four of the guys are sitting around a table playing cards and they're talking about marriage, one of the guys gets really mad and pushes the table and tries to strangle the guy at the other end of the table. All of the cards and even a bagel that were sitting on the table go flying off. But then when he calms down and sits back down, the table is perfectly in place, and the cards and bagel reappear as if they never flew off.
Continuity mistake: At the wedding the bride lifts up her arms to hug someone and you can clearly see that there are rips in the armhole of her dress (which aren't supposed to be there.