At the moment they get opened as they get given. The guests arrive over about a 20 minute period, so it spreads it out enough. Have had no real issues with other kids wanting presents etc, most of them just want to get on with playing with the other kids.

Went to a party at a play centre, the presents were not opened, just bundled up and put in the car. I had not sticky taped the card to the present (did not think there was a need), so they probably thought we had not given one. Felt mildly offended at the time.