We've never had any issues or fights with pressie opening. It's far ruder IMO when the present just disappears, you never find out if the birthday child opened it or used it or even knows who it's from. Case in point: attended one massive party where there were squillions of presents on a table, we were never thanked for the gift and in fact the thing we took was REGIFTED to my child a couple of months later. That wouldn't have happened if there had been a face to face present opening moment as the child's mother would've remembered who it was from.