If he wants to exchange presents first, let him do that instead. As the older brother, let him set the pace with whatever makes him feel most comfortable. In the days and weeks to come, you will not be able, nor would it be best, to let your older son rule the household. During these times, let him set the agenda. Not only will he feel that he has some control in life, but you will discover important things about your son.
Some children regress after a younger sibling is born.
The most common areas to be affected are eating, toileting, crying, and sleeping. The best way to deal with this is to give your son more attention for his positive big brother acts, than for his baby acts. Many children, even sweet-natured ones, expresses anger toward their younger siblings. Your son may say that he hates his little brother or sister. The reality is, he is experiencing intense emotions and needs your help to work his way through them.