Nita,

The introduction of any new animal to an existing single or group, can be a rather traumatic event for "him".

One very important issue is that you reassure him that he's not being substituted or replaced. LOTS of petting and that when the puppies are near.
Make sure he knows that you're with "him", while they're there too.

Other than that, time will make it's adjustments as the "puppy" scent diminishes in your newcomers.